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proofwiki-7200
Exclusive Or is Negation of Biconditional
Exclusive or is equivalent to the negation of the biconditional: :$p \oplus q \dashv \vdash \neg \paren {p \iff q}$
{{begin-eqn}} {{eqn | l = p \oplus q | o = \dashv \vdash | r = \paren {p \lor q} \land \neg \paren {p \land q} | c = {{Defof|Exclusive Or}} }} {{eqn | o = \dashv \vdash | r = \neg \paren {p \iff q} | c = Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction }} {{end-eq...
[[Definition:Exclusive Or|Exclusive or]] is [[Definition:Logically Equivalent|equivalent]] to the [[Definition:Logical Not|negation]] of the [[Definition:Biconditional|biconditional]]: :$p \oplus q \dashv \vdash \neg \paren {p \iff q}$
{{begin-eqn}} {{eqn | l = p \oplus q | o = \dashv \vdash | r = \paren {p \lor q} \land \neg \paren {p \land q} | c = {{Defof|Exclusive Or}} }} {{eqn | o = \dashv \vdash | r = \neg \paren {p \iff q} | c = [[Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction]] }} {{en...
Exclusive Or is Negation of Biconditional
https://proofwiki.org/wiki/Exclusive_Or_is_Negation_of_Biconditional
https://proofwiki.org/wiki/Exclusive_Or_is_Negation_of_Biconditional
[ "Exclusive Or", "Biconditional" ]
[ "Definition:Exclusive Or", "Definition:Logical Equivalence", "Definition:Logical Not", "Definition:Biconditional" ]
[ "Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction" ]
proofwiki-7201
Exclusive Or as Disjunction of Conjunctions
:$p \oplus q \dashv \vdash \paren {\neg p \land q} \lor \paren {p \land \neg q}$
{{begin-eqn}} {{eqn | l = p \oplus q | o = \dashv \vdash | r = \neg \left ({p \iff q}\right) | c = Exclusive Or is Negation of Biconditional }} {{eqn | o = \dashv \vdash | r = \left({\neg p \land q}\right) \lor \left({p \land \neg q}\right) | c = Non-Equivalence as Disjunction of Conjuncti...
:$p \oplus q \dashv \vdash \paren {\neg p \land q} \lor \paren {p \land \neg q}$
{{begin-eqn}} {{eqn | l = p \oplus q | o = \dashv \vdash | r = \neg \left ({p \iff q}\right) | c = [[Exclusive Or is Negation of Biconditional]] }} {{eqn | o = \dashv \vdash | r = \left({\neg p \land q}\right) \lor \left({p \land \neg q}\right) | c = [[Non-Equivalence as Disjunction of Con...
Exclusive Or as Disjunction of Conjunctions/Proof 1
https://proofwiki.org/wiki/Exclusive_Or_as_Disjunction_of_Conjunctions
https://proofwiki.org/wiki/Exclusive_Or_as_Disjunction_of_Conjunctions/Proof_1
[ "Exclusive Or as Disjunction of Conjunctions", "Exclusive Or", "Disjunction", "Conjunction" ]
[]
[ "Exclusive Or is Negation of Biconditional", "Non-Equivalence as Disjunction of Conjunctions/Formulation 1" ]
proofwiki-7202
Exclusive Or as Disjunction of Conjunctions
:$p \oplus q \dashv \vdash \paren {\neg p \land q} \lor \paren {p \land \neg q}$
We apply the Method of Truth Tables. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. :<nowiki>$\begin {array} {|ccc||ccccccccc|} \hline p & \oplus & q & (\neg & p & \land & q) & \lor & (p & \land & \neg & q) \\ \hline \F & \F & \F & \T & \F & \F & \F & \F...
:$p \oplus q \dashv \vdash \paren {\neg p \land q} \lor \paren {p \land \neg q}$
We apply the [[Method of Truth Tables]]. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. :<nowiki>$\begin {array} {|ccc||ccccccccc|} \h...
Exclusive Or as Disjunction of Conjunctions/Proof by Truth Table
https://proofwiki.org/wiki/Exclusive_Or_as_Disjunction_of_Conjunctions
https://proofwiki.org/wiki/Exclusive_Or_as_Disjunction_of_Conjunctions/Proof_by_Truth_Table
[ "Exclusive Or as Disjunction of Conjunctions", "Exclusive Or", "Disjunction", "Conjunction" ]
[]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7203
Non-Equivalence as Disjunction of Negated Conditionals
:$\neg \paren {p \iff q} \dashv \vdash \neg \paren {p \implies q} \lor \neg \paren {q \implies p}$
{{BeginTableau|\neg \paren {p \iff q} \vdash \neg \paren {p \implies q} \lor \neg \paren {q \implies p} }} {{Premise|1|\neg \paren {p \iff q} }} {{SequentIntro|2|1|\neg \paren {\paren {p \implies q} \land \paren {q \implies p} }|1 |Rule of Material Equivalence}} {{DeMorgan|3|1|\neg \paren {p \implies q} \lor \neg \pa...
:$\neg \paren {p \iff q} \dashv \vdash \neg \paren {p \implies q} \lor \neg \paren {q \implies p}$
{{BeginTableau|\neg \paren {p \iff q} \vdash \neg \paren {p \implies q} \lor \neg \paren {q \implies p} }} {{Premise|1|\neg \paren {p \iff q} }} {{SequentIntro|2|1|\neg \paren {\paren {p \implies q} \land \paren {q \implies p} }|1 |[[Rule of Material Equivalence]]}} {{DeMorgan|3|1|\neg \paren {p \implies q} \lor \neg...
Non-Equivalence as Disjunction of Negated Conditionals/Proof 1
https://proofwiki.org/wiki/Non-Equivalence_as_Disjunction_of_Negated_Conditionals
https://proofwiki.org/wiki/Non-Equivalence_as_Disjunction_of_Negated_Conditionals/Proof_1
[ "Non-Equivalence as Disjunction of Negated Conditionals", "Biconditional", "Disjunction", "Logical Negation", "Conditional" ]
[]
[ "Rule of Material Equivalence", "Rule of Material Equivalence" ]
proofwiki-7204
Non-Equivalence as Disjunction of Negated Conditionals
:$\neg \paren {p \iff q} \dashv \vdash \neg \paren {p \implies q} \lor \neg \paren {q \implies p}$
We apply the Method of Truth Tables. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. $\begin{array}{|cccc||ccccccccc|} \hline \neg & (p & \iff & q) & \neg & (p & \implies & q) & \lor & \neg & (q & \implies & p) \\ \hline \F & \F & \T & \F & \F & \F & \T &...
:$\neg \paren {p \iff q} \dashv \vdash \neg \paren {p \implies q} \lor \neg \paren {q \implies p}$
We apply the [[Method of Truth Tables]]. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. $\begin{array}{|cccc||ccccccccc|} \hline \neg...
Non-Equivalence as Disjunction of Negated Conditionals/Proof by Truth Table
https://proofwiki.org/wiki/Non-Equivalence_as_Disjunction_of_Negated_Conditionals
https://proofwiki.org/wiki/Non-Equivalence_as_Disjunction_of_Negated_Conditionals/Proof_by_Truth_Table
[ "Non-Equivalence as Disjunction of Negated Conditionals", "Biconditional", "Disjunction", "Logical Negation", "Conditional" ]
[]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7205
Conjunction of Disjunction with Negation is Conjunction with Negation
:$\paren {p \lor q} \land \neg q \dashv \vdash p \land \neg q$
{{BeginTableau|p \land \neg q \vdash \paren {p \lor q} \land \neg q}} {{Premise|1|p \land \neg q}} {{Simplification|2|1|p|1|1}} {{Addition|3|1|p \lor q|2|1}} {{Simplification|4|1|\neg q|1|2}} {{Conjunction|5|1|\paren {p \lor q} \land \neg q|3|4}} {{EndTableau|lemma}} and its converse: {{BeginTableau|\paren {p \lor q} \...
:$\paren {p \lor q} \land \neg q \dashv \vdash p \land \neg q$
{{BeginTableau|p \land \neg q \vdash \paren {p \lor q} \land \neg q}} {{Premise|1|p \land \neg q}} {{Simplification|2|1|p|1|1}} {{Addition|3|1|p \lor q|2|1}} {{Simplification|4|1|\neg q|1|2}} {{Conjunction|5|1|\paren {p \lor q} \land \neg q|3|4}} {{EndTableau|lemma}} and its converse: {{BeginTableau|\paren {p \lor q...
Conjunction of Disjunction with Negation is Conjunction with Negation
https://proofwiki.org/wiki/Conjunction_of_Disjunction_with_Negation_is_Conjunction_with_Negation
https://proofwiki.org/wiki/Conjunction_of_Disjunction_with_Negation_is_Conjunction_with_Negation
[ "Conjunction", "Disjunction", "Logical Negation" ]
[]
[ "Rule of Distribution/Conjunction Distributes over Disjunction", "Modus Tollendo Ponens", "Category:Conjunction", "Category:Disjunction", "Category:Logical Negation" ]
proofwiki-7206
Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction
:$\neg \paren {p \iff q} \dashv \vdash \paren {p \lor q} \land \neg \paren {p \land q}$ That is, negation of the biconditional means the same thing as '''either-or but not both''', that is, exclusive or.
{{BeginTableau|\neg \paren {p \iff q} \vdash \paren {p \lor q} \land \neg \paren {p \land q} }} {{Premise|1|\neg \paren {p \iff q} }} {{SequentIntro|2|1|\paren {\neg p \land q} \lor \paren {p \land \neg q}|1 |Non-Equivalence as Disjunction of Conjunctions: Formulation 1 }} {{Commutation|3|1|\paren {p \land \neg q} \l...
:$\neg \paren {p \iff q} \dashv \vdash \paren {p \lor q} \land \neg \paren {p \land q}$ That is, [[Definition:Logical Not|negation]] of the [[Definition:Biconditional|biconditional]] means the same thing as '''either-or but not both''', that is, [[Definition:Exclusive Or|exclusive or]].
{{BeginTableau|\neg \paren {p \iff q} \vdash \paren {p \lor q} \land \neg \paren {p \land q} }} {{Premise|1|\neg \paren {p \iff q} }} {{SequentIntro|2|1|\paren {\neg p \land q} \lor \paren {p \land \neg q}|1 |[[Non-Equivalence as Disjunction of Conjunctions/Formulation 1|Non-Equivalence as Disjunction of Conjunctions...
Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction/Proof 1
https://proofwiki.org/wiki/Non-Equivalence_as_Conjunction_of_Disjunction_with_Negation_of_Conjunction
https://proofwiki.org/wiki/Non-Equivalence_as_Conjunction_of_Disjunction_with_Negation_of_Conjunction/Proof_1
[ "Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction", "Conjunction", "Disjunction", "Logical Negation", "Biconditional" ]
[ "Definition:Logical Not", "Definition:Biconditional", "Definition:Exclusive Or" ]
[ "Non-Equivalence as Disjunction of Conjunctions/Formulation 1", "Conjunction of Disjunction with Negation is Conjunction with Negation", "Rule of Distribution/Conjunction Distributes over Disjunction", "Rule of Distribution/Conjunction Distributes over Disjunction", "Conjunction of Disjunction with Negation...
proofwiki-7207
Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction
:$\neg \paren {p \iff q} \dashv \vdash \paren {p \lor q} \land \neg \paren {p \land q}$ That is, negation of the biconditional means the same thing as '''either-or but not both''', that is, exclusive or.
We apply the Method of Truth Tables. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. $\begin{array}{|cccc||cccccccc|} \hline \neg & (p & \iff & q) & (p & \lor & q) & \land & \neg & (p & \land & q) \\ \hline \F & \F & \T & \F & \F & \F & \F & \F & \T & \F ...
:$\neg \paren {p \iff q} \dashv \vdash \paren {p \lor q} \land \neg \paren {p \land q}$ That is, [[Definition:Logical Not|negation]] of the [[Definition:Biconditional|biconditional]] means the same thing as '''either-or but not both''', that is, [[Definition:Exclusive Or|exclusive or]].
We apply the [[Method of Truth Tables]]. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. $\begin{array}{|cccc||cccccccc|} \hline \neg ...
Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction/Proof by Truth Table
https://proofwiki.org/wiki/Non-Equivalence_as_Conjunction_of_Disjunction_with_Negation_of_Conjunction
https://proofwiki.org/wiki/Non-Equivalence_as_Conjunction_of_Disjunction_with_Negation_of_Conjunction/Proof_by_Truth_Table
[ "Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction", "Conjunction", "Disjunction", "Logical Negation", "Biconditional" ]
[ "Definition:Logical Not", "Definition:Biconditional", "Definition:Exclusive Or" ]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7208
Non-Equivalence as Conjunction of Disjunction with Disjunction of Negations
:$\neg \paren {p \iff q} \dashv \vdash \paren {p \lor q} \land \paren {\neg p \lor \neg q}$
{{BeginTableau|\neg \paren {p \iff q} \vdash \paren {p \lor q} \land \paren {\neg p \lor \neg q} }} {{Premise |1|\neg \paren {p \iff q} }} {{SequentIntro|2|1|\paren {p \lor q} \land \neg \paren {p \land q}|1|Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction}} {{DeMorgan |3|1|\paren {p \l...
:$\neg \paren {p \iff q} \dashv \vdash \paren {p \lor q} \land \paren {\neg p \lor \neg q}$
{{BeginTableau|\neg \paren {p \iff q} \vdash \paren {p \lor q} \land \paren {\neg p \lor \neg q} }} {{Premise |1|\neg \paren {p \iff q} }} {{SequentIntro|2|1|\paren {p \lor q} \land \neg \paren {p \land q}|1|[[Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction]]}} {{DeMorgan |3|1|\paren {...
Non-Equivalence as Conjunction of Disjunction with Disjunction of Negations/Proof 1
https://proofwiki.org/wiki/Non-Equivalence_as_Conjunction_of_Disjunction_with_Disjunction_of_Negations
https://proofwiki.org/wiki/Non-Equivalence_as_Conjunction_of_Disjunction_with_Disjunction_of_Negations/Proof_1
[ "Non-Equivalence as Conjunction of Disjunction with Disjunction of Negations", "Conjunction", "Disjunction", "Logical Negation", "Biconditional" ]
[]
[ "Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction", "Non-Equivalence as Conjunction of Disjunction with Negation of Conjunction" ]
proofwiki-7209
Non-Equivalence as Conjunction of Disjunction with Disjunction of Negations
:$\neg \paren {p \iff q} \dashv \vdash \paren {p \lor q} \land \paren {\neg p \lor \neg q}$
We apply the Method of Truth Tables. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. $\begin{array}{|cccc||ccccccccc|} \hline \neg & (p & \iff & q) & (p & \lor & q) & \land & (\neg & p & \lor & \neg & q) \\ \hline \F & \F & \T & \F & \F & \F & \F & \F & \...
:$\neg \paren {p \iff q} \dashv \vdash \paren {p \lor q} \land \paren {\neg p \lor \neg q}$
We apply the [[Method of Truth Tables]]. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. $\begin{array}{|cccc||ccccccccc|} \hline \neg...
Non-Equivalence as Conjunction of Disjunction with Disjunction of Negations/Proof by Truth Table
https://proofwiki.org/wiki/Non-Equivalence_as_Conjunction_of_Disjunction_with_Disjunction_of_Negations
https://proofwiki.org/wiki/Non-Equivalence_as_Conjunction_of_Disjunction_with_Disjunction_of_Negations/Proof_by_Truth_Table
[ "Non-Equivalence as Conjunction of Disjunction with Disjunction of Negations", "Conjunction", "Disjunction", "Logical Negation", "Biconditional" ]
[]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7210
Inversion Mapping is Involution
Let $G$ be a group, and let $\iota: G \to G$ be the inversion mapping. Then $\iota$ is an involution. That is: :$\forall g \in G: \map \iota {\map \iota g} = g$
Let $g \in G$. Then: {{begin-eqn}} {{eqn | l = \map \iota {\map \iota g} | r = \paren {g^{-1} }^{-1} | c = {{Defof|Inversion Mapping}} }} {{eqn | r = g | c = Inverse of Group Inverse }} {{end-eqn}} which establishes the result. {{qed}} Category:Inversion Mappings scu8viz33uzskvkzuh04emh1ycpbec3
Let $G$ be a [[Definition:Group|group]], and let $\iota: G \to G$ be the [[Definition:Inversion Mapping|inversion mapping]]. Then $\iota$ is an [[Definition:Involution (Mapping)|involution]]. That is: :$\forall g \in G: \map \iota {\map \iota g} = g$
Let $g \in G$. Then: {{begin-eqn}} {{eqn | l = \map \iota {\map \iota g} | r = \paren {g^{-1} }^{-1} | c = {{Defof|Inversion Mapping}} }} {{eqn | r = g | c = [[Inverse of Group Inverse]] }} {{end-eqn}} which establishes the result. {{qed}} [[Category:Inversion Mappings]] scu8viz33uzskvkzuh04emh1yc...
Inversion Mapping is Involution
https://proofwiki.org/wiki/Inversion_Mapping_is_Involution
https://proofwiki.org/wiki/Inversion_Mapping_is_Involution
[ "Inversion Mappings" ]
[ "Definition:Group", "Definition:Inversion Mapping", "Definition:Involution (Mapping)" ]
[ "Inverse of Group Inverse", "Category:Inversion Mappings" ]
proofwiki-7211
Order Isomorphism between Linearly Ordered Spaces is Homeomorphism
Let $\struct {S_1, \le_1, \tau_1}$ and $\struct {S_2, \le_2, \tau_2}$ be linearly ordered spaces. Let $\phi: S_1 \to S_2$ be an order isomorphism from $\struct {S_1, \le_1}$ to $\struct {S_2, \le_2}$. Then $\phi$ is a homeomorphism from $\struct {S_1, \tau_1}$ to $\struct {S_2, \tau_2}$.
By the definition of order isomorphism, $\phi$ is a bijection. Thus to show $\phi$ is a homeomorphism it remains to be shown that: :$\phi$ is continuous and: :$\phi^{-1}$ is continuous. First it is shown that $\phi^{-1}$ is continuous. By Order Isomorphism Preserves Initial Segments and its dual, $\phi$ maps open rays ...
Let $\struct {S_1, \le_1, \tau_1}$ and $\struct {S_2, \le_2, \tau_2}$ be [[Definition:Linearly Ordered Space|linearly ordered spaces]]. Let $\phi: S_1 \to S_2$ be an [[Definition:Order Isomorphism|order isomorphism]] from $\struct {S_1, \le_1}$ to $\struct {S_2, \le_2}$. Then $\phi$ is a [[Definition:Homeomorphism (...
By the definition of [[Definition:Order Isomorphism|order isomorphism]], $\phi$ is a [[Definition:Bijection|bijection]]. Thus to show $\phi$ is a [[Definition:Homeomorphism (Topological Spaces)|homeomorphism]] it remains to be shown that: :$\phi$ is [[Definition:Everywhere Continuous Mapping (Topology)|continuous]] an...
Order Isomorphism between Linearly Ordered Spaces is Homeomorphism
https://proofwiki.org/wiki/Order_Isomorphism_between_Linearly_Ordered_Spaces_is_Homeomorphism
https://proofwiki.org/wiki/Order_Isomorphism_between_Linearly_Ordered_Spaces_is_Homeomorphism
[ "Linearly Ordered Spaces" ]
[ "Definition:Linearly Ordered Space", "Definition:Order Isomorphism", "Definition:Homeomorphism/Topological Spaces" ]
[ "Definition:Order Isomorphism", "Definition:Bijection", "Definition:Homeomorphism/Topological Spaces", "Definition:Continuous Mapping (Topology)/Everywhere", "Definition:Continuous Mapping (Topology)/Everywhere", "Definition:Continuous Mapping (Topology)/Everywhere", "Order Isomorphism Preserves Initial...
proofwiki-7212
Rule of Association/Conjunction
Conjunction is associative: === Formulation 1 === {{:Rule of Association/Conjunction/Formulation 1}} === Formulation 2 === {{:Rule of Association/Conjunction/Formulation 2}}
{{BeginTableau|p \land \paren {q \land r} \vdash \paren {p \land q} \land r}} {{Premise|1|p \land \paren {q \land r} }} {{Simplification|2|1|p|1|1}} {{Simplification|3|1|q \land r|1|2}} {{Simplification|4|1|q|3|1}} {{Simplification|5|1|r|3|2}} {{Conjunction|6|1|p \land q|2|4}} {{Conjunction|7|1|\paren {p \land q} \land...
[[Definition:Conjunction|Conjunction]] is [[Definition:Associative Operation|associative]]: === [[Rule of Association/Conjunction/Formulation 1|Formulation 1]] === {{:Rule of Association/Conjunction/Formulation 1}} === [[Rule of Association/Conjunction/Formulation 2|Formulation 2]] === {{:Rule of Association/Conjuncti...
{{BeginTableau|p \land \paren {q \land r} \vdash \paren {p \land q} \land r}} {{Premise|1|p \land \paren {q \land r} }} {{Simplification|2|1|p|1|1}} {{Simplification|3|1|q \land r|1|2}} {{Simplification|4|1|q|3|1}} {{Simplification|5|1|r|3|2}} {{Conjunction|6|1|p \land q|2|4}} {{Conjunction|7|1|\paren {p \land q} \land...
Rule of Association/Conjunction/Formulation 1/Proof 1
https://proofwiki.org/wiki/Rule_of_Association/Conjunction
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_1/Proof_1
[ "Rule of Association", "Conjunction" ]
[ "Definition:Conjunction", "Definition:Associative Operation", "Rule of Association/Conjunction/Formulation 1", "Rule of Association/Conjunction/Formulation 2" ]
[]
proofwiki-7213
Rule of Association/Conjunction
Conjunction is associative: === Formulation 1 === {{:Rule of Association/Conjunction/Formulation 1}} === Formulation 2 === {{:Rule of Association/Conjunction/Formulation 2}}
We apply the Method of Truth Tables. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. :<nowiki>$\begin{array}{|ccccc||ccccc|} \hline p & \land & (q & \land & r) & (p & \land & q) & \land & r \\ \hline \F & \F & \F & \F & \F & \F & \F & \F & \F & \F \\ \F &...
[[Definition:Conjunction|Conjunction]] is [[Definition:Associative Operation|associative]]: === [[Rule of Association/Conjunction/Formulation 1|Formulation 1]] === {{:Rule of Association/Conjunction/Formulation 1}} === [[Rule of Association/Conjunction/Formulation 2|Formulation 2]] === {{:Rule of Association/Conjuncti...
We apply the [[Method of Truth Tables]]. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. :<nowiki>$\begin{array}{|ccccc||ccccc|} \hline...
Rule of Association/Conjunction/Formulation 1/Proof by Truth Table
https://proofwiki.org/wiki/Rule_of_Association/Conjunction
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_1/Proof_by_Truth_Table
[ "Rule of Association", "Conjunction" ]
[ "Definition:Conjunction", "Definition:Associative Operation", "Rule of Association/Conjunction/Formulation 1", "Rule of Association/Conjunction/Formulation 2" ]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7214
Rule of Association/Conjunction
Conjunction is associative: === Formulation 1 === {{:Rule of Association/Conjunction/Formulation 1}} === Formulation 2 === {{:Rule of Association/Conjunction/Formulation 2}}
=== Forward Implication === {{:Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication}} === Reverse Implication === {{:Rule of Association/Conjunction/Formulation 2/Proof 1/Reverse Implication}} {{BeginTableau|\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r} }} {{T...
[[Definition:Conjunction|Conjunction]] is [[Definition:Associative Operation|associative]]: === [[Rule of Association/Conjunction/Formulation 1|Formulation 1]] === {{:Rule of Association/Conjunction/Formulation 1}} === [[Rule of Association/Conjunction/Formulation 2|Formulation 2]] === {{:Rule of Association/Conjuncti...
=== [[Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication|Forward Implication]] === {{:Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication}} === [[Rule of Association/Conjunction/Formulation 2/Proof 1/Reverse Implication|Reverse Implication]] === {{:Rule of Association/Conju...
Rule of Association/Conjunction/Formulation 2/Proof 1
https://proofwiki.org/wiki/Rule_of_Association/Conjunction
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_2/Proof_1
[ "Rule of Association", "Conjunction" ]
[ "Definition:Conjunction", "Definition:Associative Operation", "Rule of Association/Conjunction/Formulation 1", "Rule of Association/Conjunction/Formulation 2" ]
[ "Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication", "Rule of Association/Conjunction/Formulation 2/Proof 1/Reverse Implication", "Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication", "Rule of Association/Conjunction/Formulation 2/Proof 1/Reverse Implication" ]
proofwiki-7215
Rule of Association/Conjunction
Conjunction is associative: === Formulation 1 === {{:Rule of Association/Conjunction/Formulation 1}} === Formulation 2 === {{:Rule of Association/Conjunction/Formulation 2}}
{{BeginTableau|\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r} }} {{Assumption |1|p \land \paren {q \land r} }} {{SequentIntro|2|1|\paren {p \land q} \land r|1|Rule of Association: Formulation 1}} {{Implication |3||\paren {p \land \paren {q \land r} } \implies \paren {\paren {p \la...
[[Definition:Conjunction|Conjunction]] is [[Definition:Associative Operation|associative]]: === [[Rule of Association/Conjunction/Formulation 1|Formulation 1]] === {{:Rule of Association/Conjunction/Formulation 1}} === [[Rule of Association/Conjunction/Formulation 2|Formulation 2]] === {{:Rule of Association/Conjuncti...
{{BeginTableau|\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r} }} {{Assumption |1|p \land \paren {q \land r} }} {{SequentIntro|2|1|\paren {p \land q} \land r|1|[[Rule of Association/Conjunction/Formulation 1|Rule of Association: Formulation 1]]}} {{Implication |3||\paren {p \land \...
Rule of Association/Conjunction/Formulation 2/Proof 2
https://proofwiki.org/wiki/Rule_of_Association/Conjunction
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_2/Proof_2
[ "Rule of Association", "Conjunction" ]
[ "Definition:Conjunction", "Definition:Associative Operation", "Rule of Association/Conjunction/Formulation 1", "Rule of Association/Conjunction/Formulation 2" ]
[ "Rule of Association/Conjunction/Formulation 1", "Rule of Association/Conjunction/Formulation 1" ]
proofwiki-7216
Rule of Association/Disjunction
Disjunction is associative: === Formulation 1 === {{:Rule of Association/Disjunction/Formulation 1}} === Formulation 2 === {{:Rule of Association/Disjunction/Formulation 2}}
{{BeginTableau|p \lor \paren {q \lor r} \vdash \paren {p \lor q} \lor r}} {{Premise|1|p \lor \paren {q \lor r} }} {{Assumption|2|p|By assuming the first main disjunct ...}} {{Addition|3|2|p \lor q|2|1}} {{Addition|4|2|\paren {p \lor q} \lor r|3|1|... the conclusion is derived}} {{Assumption|5|q \lor r|Then assume the s...
[[Definition:Disjunction|Disjunction]] is [[Definition:Associative Operation|associative]]: === [[Rule of Association/Disjunction/Formulation 1|Formulation 1]] === {{:Rule of Association/Disjunction/Formulation 1}} === [[Rule of Association/Disjunction/Formulation 2|Formulation 2]] === {{:Rule of Association/Disjuncti...
{{BeginTableau|p \lor \paren {q \lor r} \vdash \paren {p \lor q} \lor r}} {{Premise|1|p \lor \paren {q \lor r} }} {{Assumption|2|p|By assuming the first main disjunct ...}} {{Addition|3|2|p \lor q|2|1}} {{Addition|4|2|\paren {p \lor q} \lor r|3|1|... the conclusion is derived}} {{Assumption|5|q \lor r|Then assume the s...
Rule of Association/Disjunction/Formulation 1/Proof 1
https://proofwiki.org/wiki/Rule_of_Association/Disjunction
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_1/Proof_1
[ "Rule of Association", "Disjunction" ]
[ "Definition:Disjunction", "Definition:Associative Operation", "Rule of Association/Disjunction/Formulation 1", "Rule of Association/Disjunction/Formulation 2" ]
[]
proofwiki-7217
Rule of Association/Disjunction
Disjunction is associative: === Formulation 1 === {{:Rule of Association/Disjunction/Formulation 1}} === Formulation 2 === {{:Rule of Association/Disjunction/Formulation 2}}
We apply the Method of Truth Tables. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. :<nowiki>$\begin{array}{|ccccc||ccccc|} \hline p & \lor & (q & \lor & r) & (p & \lor & q) & \lor & r \\ \hline \F & \F & \F & \F & \F & \F & \F & \F & \F & \F \\ \F & \T ...
[[Definition:Disjunction|Disjunction]] is [[Definition:Associative Operation|associative]]: === [[Rule of Association/Disjunction/Formulation 1|Formulation 1]] === {{:Rule of Association/Disjunction/Formulation 1}} === [[Rule of Association/Disjunction/Formulation 2|Formulation 2]] === {{:Rule of Association/Disjuncti...
We apply the [[Method of Truth Tables]]. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. :<nowiki>$\begin{array}{|ccccc||ccccc|} \hline...
Rule of Association/Disjunction/Formulation 1/Proof by Truth Table
https://proofwiki.org/wiki/Rule_of_Association/Disjunction
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_1/Proof_by_Truth_Table
[ "Rule of Association", "Disjunction" ]
[ "Definition:Disjunction", "Definition:Associative Operation", "Rule of Association/Disjunction/Formulation 1", "Rule of Association/Disjunction/Formulation 2" ]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7218
Rule of Association/Disjunction
Disjunction is associative: === Formulation 1 === {{:Rule of Association/Disjunction/Formulation 1}} === Formulation 2 === {{:Rule of Association/Disjunction/Formulation 2}}
{{BeginTableau|\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r} }} {{Assumption |1|p \lor \paren {q \lor r} }} {{SequentIntro|2|1|\paren {p \lor q} \lor r|1|Rule of Association: Formulation 1}} {{Implication |3||\paren {p \lor \paren {q \lor r} } \implies \paren {\paren {p \lor q} \lor ...
[[Definition:Disjunction|Disjunction]] is [[Definition:Associative Operation|associative]]: === [[Rule of Association/Disjunction/Formulation 1|Formulation 1]] === {{:Rule of Association/Disjunction/Formulation 1}} === [[Rule of Association/Disjunction/Formulation 2|Formulation 2]] === {{:Rule of Association/Disjuncti...
{{BeginTableau|\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r} }} {{Assumption |1|p \lor \paren {q \lor r} }} {{SequentIntro|2|1|\paren {p \lor q} \lor r|1|[[Rule of Association/Disjunction/Formulation 1|Rule of Association: Formulation 1]]}} {{Implication |3||\paren {p \lor \paren {q ...
Rule of Association/Disjunction/Formulation 2/Proof 1
https://proofwiki.org/wiki/Rule_of_Association/Disjunction
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_2/Proof_1
[ "Rule of Association", "Disjunction" ]
[ "Definition:Disjunction", "Definition:Associative Operation", "Rule of Association/Disjunction/Formulation 1", "Rule of Association/Disjunction/Formulation 2" ]
[ "Rule of Association/Disjunction/Formulation 1", "Rule of Association/Disjunction/Formulation 1" ]
proofwiki-7219
Rule of Association/Disjunction
Disjunction is associative: === Formulation 1 === {{:Rule of Association/Disjunction/Formulation 1}} === Formulation 2 === {{:Rule of Association/Disjunction/Formulation 2}}
{{BeginTableau|\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r}|Instance 2 of the Hilbert-style systems}} {{TableauLine | n = 1 | f = \paren {p \lor \paren {q \lor r} } \implies \paren {\paren {p \lor q} \lor r} | rlnk = Rule of Association/Disjunction/Formulation 2/Forward Implicatio...
[[Definition:Disjunction|Disjunction]] is [[Definition:Associative Operation|associative]]: === [[Rule of Association/Disjunction/Formulation 1|Formulation 1]] === {{:Rule of Association/Disjunction/Formulation 1}} === [[Rule of Association/Disjunction/Formulation 2|Formulation 2]] === {{:Rule of Association/Disjuncti...
{{BeginTableau|\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r}|[[Definition:Hilbert Proof System/Instance 2|Instance 2 of the Hilbert-style systems]]}} {{TableauLine | n = 1 | f = \paren {p \lor \paren {q \lor r} } \implies \paren {\paren {p \lor q} \lor r} | rlnk = Rule of Associati...
Rule of Association/Disjunction/Formulation 2/Proof 2
https://proofwiki.org/wiki/Rule_of_Association/Disjunction
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_2/Proof_2
[ "Rule of Association", "Disjunction" ]
[ "Definition:Disjunction", "Definition:Associative Operation", "Rule of Association/Disjunction/Formulation 1", "Rule of Association/Disjunction/Formulation 2" ]
[ "Definition:Hilbert Proof System/Instance 2" ]
proofwiki-7220
Rule of Association/Conjunction/Formulation 1
:$p \land \paren {q \land r} \dashv \vdash \paren {p \land q} \land r$
{{BeginTableau|p \land \paren {q \land r} \vdash \paren {p \land q} \land r}} {{Premise|1|p \land \paren {q \land r} }} {{Simplification|2|1|p|1|1}} {{Simplification|3|1|q \land r|1|2}} {{Simplification|4|1|q|3|1}} {{Simplification|5|1|r|3|2}} {{Conjunction|6|1|p \land q|2|4}} {{Conjunction|7|1|\paren {p \land q} \land...
:$p \land \paren {q \land r} \dashv \vdash \paren {p \land q} \land r$
{{BeginTableau|p \land \paren {q \land r} \vdash \paren {p \land q} \land r}} {{Premise|1|p \land \paren {q \land r} }} {{Simplification|2|1|p|1|1}} {{Simplification|3|1|q \land r|1|2}} {{Simplification|4|1|q|3|1}} {{Simplification|5|1|r|3|2}} {{Conjunction|6|1|p \land q|2|4}} {{Conjunction|7|1|\paren {p \land q} \land...
Rule of Association/Conjunction/Formulation 1/Proof 1
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_1
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_1/Proof_1
[ "Rule of Association" ]
[]
[]
proofwiki-7221
Rule of Association/Conjunction/Formulation 1
:$p \land \paren {q \land r} \dashv \vdash \paren {p \land q} \land r$
We apply the Method of Truth Tables. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. :<nowiki>$\begin{array}{|ccccc||ccccc|} \hline p & \land & (q & \land & r) & (p & \land & q) & \land & r \\ \hline \F & \F & \F & \F & \F & \F & \F & \F & \F & \F \\ \F &...
:$p \land \paren {q \land r} \dashv \vdash \paren {p \land q} \land r$
We apply the [[Method of Truth Tables]]. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. :<nowiki>$\begin{array}{|ccccc||ccccc|} \hline...
Rule of Association/Conjunction/Formulation 1/Proof by Truth Table
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_1
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_1/Proof_by_Truth_Table
[ "Rule of Association" ]
[]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7222
Rule of Association/Disjunction/Formulation 1
:$p \lor \paren {q \lor r} \dashv \vdash \paren {p \lor q} \lor r$
{{BeginTableau|p \lor \paren {q \lor r} \vdash \paren {p \lor q} \lor r}} {{Premise|1|p \lor \paren {q \lor r} }} {{Assumption|2|p|By assuming the first main disjunct ...}} {{Addition|3|2|p \lor q|2|1}} {{Addition|4|2|\paren {p \lor q} \lor r|3|1|... the conclusion is derived}} {{Assumption|5|q \lor r|Then assume the s...
:$p \lor \paren {q \lor r} \dashv \vdash \paren {p \lor q} \lor r$
{{BeginTableau|p \lor \paren {q \lor r} \vdash \paren {p \lor q} \lor r}} {{Premise|1|p \lor \paren {q \lor r} }} {{Assumption|2|p|By assuming the first main disjunct ...}} {{Addition|3|2|p \lor q|2|1}} {{Addition|4|2|\paren {p \lor q} \lor r|3|1|... the conclusion is derived}} {{Assumption|5|q \lor r|Then assume the s...
Rule of Association/Disjunction/Formulation 1/Proof 1
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_1
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_1/Proof_1
[ "Rule of Association" ]
[]
[]
proofwiki-7223
Rule of Association/Disjunction/Formulation 1
:$p \lor \paren {q \lor r} \dashv \vdash \paren {p \lor q} \lor r$
We apply the Method of Truth Tables. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. :<nowiki>$\begin{array}{|ccccc||ccccc|} \hline p & \lor & (q & \lor & r) & (p & \lor & q) & \lor & r \\ \hline \F & \F & \F & \F & \F & \F & \F & \F & \F & \F \\ \F & \T ...
:$p \lor \paren {q \lor r} \dashv \vdash \paren {p \lor q} \lor r$
We apply the [[Method of Truth Tables]]. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. :<nowiki>$\begin{array}{|ccccc||ccccc|} \hline...
Rule of Association/Disjunction/Formulation 1/Proof by Truth Table
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_1
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_1/Proof_by_Truth_Table
[ "Rule of Association" ]
[]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7224
Rule of Association/Conjunction/Formulation 1/Proof 1
:$p \land \paren {q \land r} \dashv \vdash \paren {p \land q} \land r$
{{BeginTableau|p \land \paren {q \land r} \vdash \paren {p \land q} \land r}} {{Premise|1|p \land \paren {q \land r} }} {{Simplification|2|1|p|1|1}} {{Simplification|3|1|q \land r|1|2}} {{Simplification|4|1|q|3|1}} {{Simplification|5|1|r|3|2}} {{Conjunction|6|1|p \land q|2|4}} {{Conjunction|7|1|\paren {p \land q} \land...
:$p \land \paren {q \land r} \dashv \vdash \paren {p \land q} \land r$
{{BeginTableau|p \land \paren {q \land r} \vdash \paren {p \land q} \land r}} {{Premise|1|p \land \paren {q \land r} }} {{Simplification|2|1|p|1|1}} {{Simplification|3|1|q \land r|1|2}} {{Simplification|4|1|q|3|1}} {{Simplification|5|1|r|3|2}} {{Conjunction|6|1|p \land q|2|4}} {{Conjunction|7|1|\paren {p \land q} \land...
Rule of Association/Conjunction/Formulation 1/Proof 1
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_1/Proof_1
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_1/Proof_1
[ "Rule of Association" ]
[]
[]
proofwiki-7225
Rule of Association/Conjunction/Formulation 2
:$\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r}$
=== Forward Implication === {{:Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication}} === Reverse Implication === {{:Rule of Association/Conjunction/Formulation 2/Proof 1/Reverse Implication}} {{BeginTableau|\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r} }} {{T...
:$\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r}$
=== [[Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication|Forward Implication]] === {{:Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication}} === [[Rule of Association/Conjunction/Formulation 2/Proof 1/Reverse Implication|Reverse Implication]] === {{:Rule of Association/Conju...
Rule of Association/Conjunction/Formulation 2/Proof 1
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_2
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_2/Proof_1
[ "Rule of Association" ]
[]
[ "Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication", "Rule of Association/Conjunction/Formulation 2/Proof 1/Reverse Implication", "Rule of Association/Conjunction/Formulation 2/Proof 1/Forward Implication", "Rule of Association/Conjunction/Formulation 2/Proof 1/Reverse Implication" ]
proofwiki-7226
Rule of Association/Conjunction/Formulation 2
:$\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r}$
{{BeginTableau|\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r} }} {{Assumption |1|p \land \paren {q \land r} }} {{SequentIntro|2|1|\paren {p \land q} \land r|1|Rule of Association: Formulation 1}} {{Implication |3||\paren {p \land \paren {q \land r} } \implies \paren {\paren {p \la...
:$\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r}$
{{BeginTableau|\vdash \paren {p \land \paren {q \land r} } \iff \paren {\paren {p \land q} \land r} }} {{Assumption |1|p \land \paren {q \land r} }} {{SequentIntro|2|1|\paren {p \land q} \land r|1|[[Rule of Association/Conjunction/Formulation 1|Rule of Association: Formulation 1]]}} {{Implication |3||\paren {p \land \...
Rule of Association/Conjunction/Formulation 2/Proof 2
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_2
https://proofwiki.org/wiki/Rule_of_Association/Conjunction/Formulation_2/Proof_2
[ "Rule of Association" ]
[]
[ "Rule of Association/Conjunction/Formulation 1", "Rule of Association/Conjunction/Formulation 1" ]
proofwiki-7227
Rule of Association/Disjunction/Formulation 2
:$\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r}$
{{BeginTableau|\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r} }} {{Assumption |1|p \lor \paren {q \lor r} }} {{SequentIntro|2|1|\paren {p \lor q} \lor r|1|Rule of Association: Formulation 1}} {{Implication |3||\paren {p \lor \paren {q \lor r} } \implies \paren {\paren {p \lor q} \lor ...
:$\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r}$
{{BeginTableau|\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r} }} {{Assumption |1|p \lor \paren {q \lor r} }} {{SequentIntro|2|1|\paren {p \lor q} \lor r|1|[[Rule of Association/Disjunction/Formulation 1|Rule of Association: Formulation 1]]}} {{Implication |3||\paren {p \lor \paren {q ...
Rule of Association/Disjunction/Formulation 2/Proof 1
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_2
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_2/Proof_1
[ "Rule of Association" ]
[]
[ "Rule of Association/Disjunction/Formulation 1", "Rule of Association/Disjunction/Formulation 1" ]
proofwiki-7228
Rule of Association/Disjunction/Formulation 2
:$\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r}$
{{BeginTableau|\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r}|Instance 2 of the Hilbert-style systems}} {{TableauLine | n = 1 | f = \paren {p \lor \paren {q \lor r} } \implies \paren {\paren {p \lor q} \lor r} | rlnk = Rule of Association/Disjunction/Formulation 2/Forward Implicatio...
:$\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r}$
{{BeginTableau|\vdash \paren {p \lor \paren {q \lor r} } \iff \paren {\paren {p \lor q} \lor r}|[[Definition:Hilbert Proof System/Instance 2|Instance 2 of the Hilbert-style systems]]}} {{TableauLine | n = 1 | f = \paren {p \lor \paren {q \lor r} } \implies \paren {\paren {p \lor q} \lor r} | rlnk = Rule of Associati...
Rule of Association/Disjunction/Formulation 2/Proof 2
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_2
https://proofwiki.org/wiki/Rule_of_Association/Disjunction/Formulation_2/Proof_2
[ "Rule of Association" ]
[]
[ "Definition:Hilbert Proof System/Instance 2" ]
proofwiki-7229
Principle of Commutation/Formulation 1/Forward Implication
:$p \implies \paren {q \implies r} \vdash q \implies \paren {p \implies r}$
{{BeginTableau|p \implies \paren {q \implies r} \vdash q \implies \paren {p \implies r} }} {{Premise|1|p \implies \paren {q \implies r} }} {{Assumption|2|q}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|p \implies r|3|5}} {{Implication|7|1|q \implies \p...
:$p \implies \paren {q \implies r} \vdash q \implies \paren {p \implies r}$
{{BeginTableau|p \implies \paren {q \implies r} \vdash q \implies \paren {p \implies r} }} {{Premise|1|p \implies \paren {q \implies r} }} {{Assumption|2|q}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|p \implies r|3|5}} {{Implication|7|1|q \implies \p...
Principle of Commutation/Formulation 1/Forward Implication/Proof
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1/Forward_Implication
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1/Forward_Implication/Proof
[ "Principle of Commutation" ]
[]
[]
proofwiki-7230
Principle of Commutation/Formulation 1
:$p \implies \paren {q \implies r} \dashv \vdash q \implies \paren {p \implies r}$
{{BeginTableau|p \implies \paren {q \implies r} \vdash q \implies \paren {p \implies r} }} {{Premise|1|p \implies \paren {q \implies r} }} {{Assumption|2|q}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|p \implies r|3|5}} {{Implication|7|1|q \implies \p...
:$p \implies \paren {q \implies r} \dashv \vdash q \implies \paren {p \implies r}$
{{BeginTableau|p \implies \paren {q \implies r} \vdash q \implies \paren {p \implies r} }} {{Premise|1|p \implies \paren {q \implies r} }} {{Assumption|2|q}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|p \implies r|3|5}} {{Implication|7|1|q \implies \p...
Principle of Commutation/Formulation 1/Forward Implication/Proof
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1/Forward_Implication/Proof
[ "Principle of Commutation" ]
[]
[]
proofwiki-7231
Principle of Commutation/Formulation 1
:$p \implies \paren {q \implies r} \dashv \vdash q \implies \paren {p \implies r}$
We apply the Method of Truth Tables to the proposition. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. :<nowiki>$\begin{array}{|ccccc||ccccc|} \hline p & \implies & (q & \implies & r) & q & \implies & (p & \implies & r) \\ \hline \F & \T & \F & \T & \F &...
:$p \implies \paren {q \implies r} \dashv \vdash q \implies \paren {p \implies r}$
We apply the [[Method of Truth Tables]] to the proposition. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. :<nowiki>$\begin{array}{|cc...
Principle of Commutation/Formulation 1/Proof by Truth Table
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1/Proof_by_Truth_Table
[ "Principle of Commutation" ]
[]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7232
Principle of Commutation/Formulation 1
:$p \implies \paren {q \implies r} \dashv \vdash q \implies \paren {p \implies r}$
{{BeginTableau|q \implies \paren {p \implies r} \vdash p \implies \paren {q \implies r} }} {{Premise|1|q \implies \paren {p \implies r} }} {{Assumption|2|p}} {{Assumption|3|q}} {{ModusPonens|4|1, 3|p \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|q \implies r|3|5}} {{Implication|7|1|p \implies \p...
:$p \implies \paren {q \implies r} \dashv \vdash q \implies \paren {p \implies r}$
{{BeginTableau|q \implies \paren {p \implies r} \vdash p \implies \paren {q \implies r} }} {{Premise|1|q \implies \paren {p \implies r} }} {{Assumption|2|p}} {{Assumption|3|q}} {{ModusPonens|4|1, 3|p \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|q \implies r|3|5}} {{Implication|7|1|p \implies \p...
Principle of Commutation/Formulation 1/Reverse Implication/Proof
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1/Reverse_Implication/Proof
[ "Principle of Commutation" ]
[]
[]
proofwiki-7233
Principle of Commutation/Formulation 1/Reverse Implication
:$q \implies \paren {p \implies r} \vdash p \implies \paren {q \implies r}$
{{BeginTableau|q \implies \paren {p \implies r} \vdash p \implies \paren {q \implies r} }} {{Premise|1|q \implies \paren {p \implies r} }} {{Assumption|2|p}} {{Assumption|3|q}} {{ModusPonens|4|1, 3|p \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|q \implies r|3|5}} {{Implication|7|1|p \implies \p...
:$q \implies \paren {p \implies r} \vdash p \implies \paren {q \implies r}$
{{BeginTableau|q \implies \paren {p \implies r} \vdash p \implies \paren {q \implies r} }} {{Premise|1|q \implies \paren {p \implies r} }} {{Assumption|2|p}} {{Assumption|3|q}} {{ModusPonens|4|1, 3|p \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|q \implies r|3|5}} {{Implication|7|1|p \implies \p...
Principle of Commutation/Formulation 1/Reverse Implication/Proof
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1/Reverse_Implication
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_1/Reverse_Implication/Proof
[ "Principle of Commutation" ]
[]
[]
proofwiki-7234
Principle of Commutation/Formulation 2
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} } }} {{TheoremIntro|1|\paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} }|Principle of Commutation: Formulation 2: Forward Implication}} {{TheoremIntro|2|\paren {q \i...
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} } }} {{TheoremIntro|1|\paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} }|[[Principle of Commutation/Formulation 2/Forward Implication/Proof 1|Principle of Commutatio...
Principle of Commutation/Formulation 2
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2
[ "Principle of Commutation" ]
[]
[ "Principle of Commutation/Formulation 2/Forward Implication/Proof 1", "Principle of Commutation/Formulation 2/Reverse Implication/Proof" ]
proofwiki-7235
Principle of Commutation/Formulation 2
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \implies r} }} {{SequentIntro|2|1|q \implies \paren {p \implies r}|1|Principle of Commutation: Formulation 1: Forward Implication}} {{Implication|3||\paren {p \impl...
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \implies r} }} {{SequentIntro|2|1|q \implies \paren {p \implies r}|1|[[Principle of Commutation/Formulation 1/Forward Implication|Principle of Commutation: Formulat...
Principle of Commutation/Formulation 2/Forward Implication/Proof 1
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Forward_Implication/Proof_1
[ "Principle of Commutation" ]
[]
[ "Principle of Commutation/Formulation 1/Forward Implication" ]
proofwiki-7236
Principle of Commutation/Formulation 2
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \implies r} }} {{Assumption|2|q}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|p \implies r|3|5}}...
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \implies r} }} {{Assumption|2|q}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|p \implies r|3|5}}...
Principle of Commutation/Formulation 2/Forward Implication/Proof 2
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Forward_Implication/Proof_2
[ "Principle of Commutation" ]
[]
[]
proofwiki-7237
Principle of Commutation/Formulation 2
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
Using a tableau proof for instance 1 of a Hilbert proof system: {{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } |nohead = 1}} {{Assumption|1|p}} {{Assumption|2|p \implies \paren {q \implies r} }} {{ModusPonens|3|1, 2|q \implies r|1|2}} {{Assumption|4|...
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
Using a [[Definition:Tableau Proof (Formal Systems)|tableau proof]] for [[Definition:Hilbert Proof System/Instance 1|instance 1 of a Hilbert proof system]]: {{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } |nohead = 1}} {{Assumption|1|p}} {{Assumption...
Principle of Commutation/Formulation 2/Forward Implication/Proof 3
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Forward_Implication/Proof_3
[ "Principle of Commutation" ]
[]
[ "Definition:Tableau Proof (Natural Deduction)", "Definition:Hilbert Proof System/Instance 1" ]
proofwiki-7238
Principle of Commutation/Formulation 2
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {q \implies \paren {p \implies r} } \implies \paren {p \implies \paren {q \implies r} } }} {{Assumption |1|q \implies \paren {p \implies r} }} {{SequentIntro |2|1|p \implies \paren {q \implies r}|1|Principle of Commutation: Formulation 1: Reverse Implication}} {{Implication |3| |\paren {...
:$\vdash \paren {p \implies \paren {q \implies r} } \iff \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {q \implies \paren {p \implies r} } \implies \paren {p \implies \paren {q \implies r} } }} {{Assumption |1|q \implies \paren {p \implies r} }} {{SequentIntro |2|1|p \implies \paren {q \implies r}|1|[[Principle of Commutation/Formulation 1/Reverse Implication|Principle of Commutation: Form...
Principle of Commutation/Formulation 2/Reverse Implication/Proof
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Reverse_Implication/Proof
[ "Principle of Commutation" ]
[]
[ "Principle of Commutation/Formulation 1/Reverse Implication" ]
proofwiki-7239
Principle of Commutation/Formulation 2/Forward Implication
:$\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \implies r} }} {{SequentIntro|2|1|q \implies \paren {p \implies r}|1|Principle of Commutation: Formulation 1: Forward Implication}} {{Implication|3||\paren {p \impl...
:$\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \implies r} }} {{SequentIntro|2|1|q \implies \paren {p \implies r}|1|[[Principle of Commutation/Formulation 1/Forward Implication|Principle of Commutation: Formulat...
Principle of Commutation/Formulation 2/Forward Implication/Proof 1
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Forward_Implication
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Forward_Implication/Proof_1
[ "Principle of Commutation" ]
[]
[ "Principle of Commutation/Formulation 1/Forward Implication" ]
proofwiki-7240
Principle of Commutation/Formulation 2/Forward Implication
:$\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \implies r} }} {{Assumption|2|q}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|p \implies r|3|5}}...
:$\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \implies r} }} {{Assumption|2|q}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q \implies r|1|3}} {{ModusPonens|5|1, 2, 3|r|2|4}} {{Implication|6|1, 2|p \implies r|3|5}}...
Principle of Commutation/Formulation 2/Forward Implication/Proof 2
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Forward_Implication
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Forward_Implication/Proof_2
[ "Principle of Commutation" ]
[]
[]
proofwiki-7241
Principle of Commutation/Formulation 2/Forward Implication
:$\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} }$
Using a tableau proof for instance 1 of a Hilbert proof system: {{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } |nohead = 1}} {{Assumption|1|p}} {{Assumption|2|p \implies \paren {q \implies r} }} {{ModusPonens|3|1, 2|q \implies r|1|2}} {{Assumption|4|...
:$\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} }$
Using a [[Definition:Tableau Proof (Formal Systems)|tableau proof]] for [[Definition:Hilbert Proof System/Instance 1|instance 1 of a Hilbert proof system]]: {{BeginTableau|\vdash \paren {p \implies \paren {q \implies r} } \implies \paren {q \implies \paren {p \implies r} } |nohead = 1}} {{Assumption|1|p}} {{Assumption...
Principle of Commutation/Formulation 2/Forward Implication/Proof 3
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Forward_Implication
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Forward_Implication/Proof_3
[ "Principle of Commutation" ]
[]
[ "Definition:Tableau Proof (Natural Deduction)", "Definition:Hilbert Proof System/Instance 1" ]
proofwiki-7242
Principle of Commutation/Formulation 2/Reverse Implication
:$\vdash \paren {q \implies \paren {p \implies r} } \implies \paren {p \implies \paren {q \implies r} }$
{{BeginTableau|\vdash \paren {q \implies \paren {p \implies r} } \implies \paren {p \implies \paren {q \implies r} } }} {{Assumption |1|q \implies \paren {p \implies r} }} {{SequentIntro |2|1|p \implies \paren {q \implies r}|1|Principle of Commutation: Formulation 1: Reverse Implication}} {{Implication |3| |\paren {...
:$\vdash \paren {q \implies \paren {p \implies r} } \implies \paren {p \implies \paren {q \implies r} }$
{{BeginTableau|\vdash \paren {q \implies \paren {p \implies r} } \implies \paren {p \implies \paren {q \implies r} } }} {{Assumption |1|q \implies \paren {p \implies r} }} {{SequentIntro |2|1|p \implies \paren {q \implies r}|1|[[Principle of Commutation/Formulation 1/Reverse Implication|Principle of Commutation: Form...
Principle of Commutation/Formulation 2/Reverse Implication/Proof
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Reverse_Implication
https://proofwiki.org/wiki/Principle_of_Commutation/Formulation_2/Reverse_Implication/Proof
[ "Principle of Commutation" ]
[]
[ "Principle of Commutation/Formulation 1/Reverse Implication" ]
proofwiki-7243
Linearly Ordered Space is Connected iff Linear Continuum
Let $T = \struct {S, \preceq, \tau}$ be a linearly ordered space. Then $S$ is a connected space {{iff}} it is a linear continuum.
{{explain|It is not clear how the premises of the subproofs (e.g. "$T$ is disconnected and densely ordered" directly relate to the premises of the main theorem, e.g.: "$S$ is a connected space..."}}
Let $T = \struct {S, \preceq, \tau}$ be a [[Definition:Linearly Ordered Space|linearly ordered space]]. Then $S$ is a [[Definition:Connected Topological Space|connected space]] {{iff}} it is a [[Definition:Linear Continuum|linear continuum]].
{{explain|It is not clear how the premises of the subproofs (e.g. "$T$ is [[Definition:Disconnected Space|disconnected]] and [[Definition:Densely Ordered|densely ordered]]" directly relate to the premises of the main theorem, e.g.: "$S$ is a [[Definition:Connected Topological Space|connected space]]..."}}
Linearly Ordered Space is Connected iff Linear Continuum
https://proofwiki.org/wiki/Linearly_Ordered_Space_is_Connected_iff_Linear_Continuum
https://proofwiki.org/wiki/Linearly_Ordered_Space_is_Connected_iff_Linear_Continuum
[ "Linearly Ordered Spaces", "Examples of Connected Topological Spaces", "Examples of Linear Continua" ]
[ "Definition:Linearly Ordered Space", "Definition:Connected Topological Space", "Definition:Linear Continuum" ]
[ "Definition:Disconnected (Topology)/Topological Space", "Definition:Densely Ordered", "Definition:Connected Topological Space", "Definition:Disconnected (Topology)/Topological Space", "Definition:Densely Ordered", "Definition:Densely Ordered", "Definition:Densely Ordered", "Definition:Densely Ordered"...
proofwiki-7244
Rule of Transposition/Variant 1/Formulation 2/Forward Implication
:$\vdash \paren {p \implies \neg q} \implies \paren {q \implies \neg p}$
{{BeginTableau|\vdash \paren {p \implies \neg q} \implies \paren {q \implies \neg p} }} {{Assumption|1|p \implies \neg q}} {{Assumption|2|q}} {{DoubleNegIntro|3|2|\neg \neg q|2}} {{ModusTollens|4|1, 2|\neg p|1|3}} {{Implication|5|1|q \implies \neg p|2|4}} {{Implication|6||\paren {p \implies \neg q} \implies \paren {q \...
:$\vdash \paren {p \implies \neg q} \implies \paren {q \implies \neg p}$
{{BeginTableau|\vdash \paren {p \implies \neg q} \implies \paren {q \implies \neg p} }} {{Assumption|1|p \implies \neg q}} {{Assumption|2|q}} {{DoubleNegIntro|3|2|\neg \neg q|2}} {{ModusTollens|4|1, 2|\neg p|1|3}} {{Implication|5|1|q \implies \neg p|2|4}} {{Implication|6||\paren {p \implies \neg q} \implies \paren {q \...
Rule of Transposition/Variant 1/Formulation 2/Forward Implication/Proof
https://proofwiki.org/wiki/Rule_of_Transposition/Variant_1/Formulation_2/Forward_Implication
https://proofwiki.org/wiki/Rule_of_Transposition/Variant_1/Formulation_2/Forward_Implication/Proof
[ "Rule of Transposition" ]
[]
[]
proofwiki-7245
Boundary of Polygon is Jordan Curve
Let $P$ be a polygon embedded in $\R^2$. Then there exists a Jordan curve $\gamma: \closedint 0 1 \to \R^2$ such that the image of $\gamma$ is equal to the boundary $\partial P$ of $P$.
The polygon $P$ has $n$ sides, where $n \in \N$. Denote the vertices of $P$ as $A_1, \ldots, A_n$ and its sides as $S_1, \ldots, S_n$, such that each vertex $A_i$ has adjacent sides $S_{i - 1}$ and $S_i$. We use the conventions that $S_0 = S_n$, and $A_{n + 1} = A_1$. As each side $S_i$ is a line segment joining $A_i$ ...
Let $P$ be a [[Definition:Polygon|polygon]] embedded in $\R^2$. Then there exists a [[Definition:Jordan Curve|Jordan curve]] $\gamma: \closedint 0 1 \to \R^2$ such that the [[Definition:Image of Mapping|image]] of $\gamma$ is equal to the [[Definition:Boundary (Geometry)|boundary]] $\partial P$ of $P$.
The [[Definition:Polygon|polygon]] $P$ has $n$ [[Definition:Side of Polygon|sides]], where $n \in \N$. Denote the [[Definition:Vertex of Polygon|vertices]] of $P$ as $A_1, \ldots, A_n$ and its sides as $S_1, \ldots, S_n$, such that each [[Definition:Vertex of Polygon|vertex]] $A_i$ has [[Definition:Adjacent Side to Ve...
Boundary of Polygon is Jordan Curve
https://proofwiki.org/wiki/Boundary_of_Polygon_is_Jordan_Curve
https://proofwiki.org/wiki/Boundary_of_Polygon_is_Jordan_Curve
[ "Jordan Curves" ]
[ "Definition:Polygon", "Definition:Jordan Curve", "Definition:Image (Set Theory)/Mapping/Mapping", "Definition:Boundary (Geometry)" ]
[ "Definition:Polygon", "Definition:Polygon/Side", "Definition:Polygon/Vertex", "Definition:Polygon/Vertex", "Definition:Polygon/Adjacent/Side to Vertex", "Definition:Convex Set (Vector Space)/Line Segment", "Definition:Path (Topology)", "Definition:Image (Set Theory)/Mapping/Mapping", "Definition:Pol...
proofwiki-7246
Rule of Explosion/Variant 1
:$\vdash p \implies \paren {\neg p \implies q}$
{{BeginTableau|\vdash p \implies \paren {\neg p \implies q} }} {{Assumption|1|p}} {{Assumption|2|\neg p}} {{NonContradiction|3|1, 2|1|2}} {{Explosion|4|1, 2|q|3}} {{Implication|5|1|\neg p \implies q|2|4}} {{Implication|6||p \implies \paren {\neg p \implies q}|1|5}} {{EndTableau|qed}}
:$\vdash p \implies \paren {\neg p \implies q}$
{{BeginTableau|\vdash p \implies \paren {\neg p \implies q} }} {{Assumption|1|p}} {{Assumption|2|\neg p}} {{NonContradiction|3|1, 2|1|2}} {{Explosion|4|1, 2|q|3}} {{Implication|5|1|\neg p \implies q|2|4}} {{Implication|6||p \implies \paren {\neg p \implies q}|1|5}} {{EndTableau|qed}}
Rule of Explosion/Variant 1
https://proofwiki.org/wiki/Rule_of_Explosion/Variant_1
https://proofwiki.org/wiki/Rule_of_Explosion/Variant_1
[ "Rule of Explosion" ]
[]
[]
proofwiki-7247
Negation of Conditional implies Antecedent
:$\vdash \neg \paren {p \implies q} \implies p$
{{BeginTableau|\vdash \neg \paren {p \implies q} \implies p}} {{Assumption|1|\neg \paren {p \implies q} }} {{Assumption|2|\neg \paren {p \land \neg q} }} {{SequentIntro|3|2|p \implies q|2|Conditional is Equivalent to Negation of Conjunction with Negative}} {{NonContradiction|4|1, 2|3|1}} {{Reductio|5|1|p \land \neg q|2...
:$\vdash \neg \paren {p \implies q} \implies p$
{{BeginTableau|\vdash \neg \paren {p \implies q} \implies p}} {{Assumption|1|\neg \paren {p \implies q} }} {{Assumption|2|\neg \paren {p \land \neg q} }} {{SequentIntro|3|2|p \implies q|2|[[Conditional is Equivalent to Negation of Conjunction with Negative]]}} {{NonContradiction|4|1, 2|3|1}} {{Reductio|5|1|p \land \neg...
Negation of Conditional implies Antecedent/Proof 1
https://proofwiki.org/wiki/Negation_of_Conditional_implies_Antecedent
https://proofwiki.org/wiki/Negation_of_Conditional_implies_Antecedent/Proof_1
[ "Negation of Conditional implies Antecedent", "Conditional", "Logical Negation" ]
[]
[ "Conditional is Equivalent to Negation of Conjunction with Negative" ]
proofwiki-7248
Negation of Conditional implies Antecedent
:$\vdash \neg \paren {p \implies q} \implies p$
{{BeginTableau|\vdash \neg \paren {p \implies q} \implies p}} {{Assumption|1|\neg \paren {p \implies q} }} {{SequentIntro|2|1|p \land \neg q|1|Conjunction with Negative is Equivalent to Negation of Conditional}} {{Simplification|3|1|p|2|1}} {{Implication|4||\neg \paren {p \implies q} \implies p|1|3}} {{EndTableau|qed}}
:$\vdash \neg \paren {p \implies q} \implies p$
{{BeginTableau|\vdash \neg \paren {p \implies q} \implies p}} {{Assumption|1|\neg \paren {p \implies q} }} {{SequentIntro|2|1|p \land \neg q|1|[[Conjunction with Negative is Equivalent to Negation of Conditional]]}} {{Simplification|3|1|p|2|1}} {{Implication|4||\neg \paren {p \implies q} \implies p|1|3}} {{EndTableau|q...
Negation of Conditional implies Antecedent/Proof 2
https://proofwiki.org/wiki/Negation_of_Conditional_implies_Antecedent
https://proofwiki.org/wiki/Negation_of_Conditional_implies_Antecedent/Proof_2
[ "Negation of Conditional implies Antecedent", "Conditional", "Logical Negation" ]
[]
[ "Conjunction with Negative is Equivalent to Negation of Conditional" ]
proofwiki-7249
Negation of Conditional implies Negation of Consequent
:$\vdash \neg \paren {p \implies q} \implies \neg q$
{{BeginTableau|\vdash \neg \paren {p \implies q} \implies \neg q}} {{Assumption|1|\neg \paren {p \implies q} }} {{Assumption|2|\neg \paren {p \land \neg q} }} {{SequentIntro|3|2|p \implies q|2|Conditional is Equivalent to Negation of Conjunction with Negative}} {{NonContradiction|4|1, 2|3|1}} {{Reductio|5|1|p \land \ne...
:$\vdash \neg \paren {p \implies q} \implies \neg q$
{{BeginTableau|\vdash \neg \paren {p \implies q} \implies \neg q}} {{Assumption|1|\neg \paren {p \implies q} }} {{Assumption|2|\neg \paren {p \land \neg q} }} {{SequentIntro|3|2|p \implies q|2|[[Conditional is Equivalent to Negation of Conjunction with Negative]]}} {{NonContradiction|4|1, 2|3|1}} {{Reductio|5|1|p \land...
Negation of Conditional implies Negation of Consequent/Proof 1
https://proofwiki.org/wiki/Negation_of_Conditional_implies_Negation_of_Consequent
https://proofwiki.org/wiki/Negation_of_Conditional_implies_Negation_of_Consequent/Proof_1
[ "Negation of Conditional implies Negation of Consequent", "Conditional", "Logical Negation" ]
[]
[ "Conditional is Equivalent to Negation of Conjunction with Negative" ]
proofwiki-7250
Negation of Conditional implies Negation of Consequent
:$\vdash \neg \paren {p \implies q} \implies \neg q$
{{BeginTableau|\vdash \neg \paren {p \implies q} \implies \neg q}} {{Assumption|1|\neg \paren {p \implies q} }} {{SequentIntro|2|1|p \land \neg q|1|Conjunction with Negative is Equivalent to Negation of Conditional}} {{Simplification|3|1|\neg q|2|2}} {{Implication|4||\neg \paren {p \implies q} \implies \neg q|1|3}} {{E...
:$\vdash \neg \paren {p \implies q} \implies \neg q$
{{BeginTableau|\vdash \neg \paren {p \implies q} \implies \neg q}} {{Assumption|1|\neg \paren {p \implies q} }} {{SequentIntro|2|1|p \land \neg q|1|[[Conjunction with Negative is Equivalent to Negation of Conditional]]}} {{Simplification|3|1|\neg q|2|2}} {{Implication|4||\neg \paren {p \implies q} \implies \neg q|1|3}}...
Negation of Conditional implies Negation of Consequent/Proof 2
https://proofwiki.org/wiki/Negation_of_Conditional_implies_Negation_of_Consequent
https://proofwiki.org/wiki/Negation_of_Conditional_implies_Negation_of_Consequent/Proof_2
[ "Negation of Conditional implies Negation of Consequent", "Conditional", "Logical Negation" ]
[]
[ "Conjunction with Negative is Equivalent to Negation of Conditional" ]
proofwiki-7251
Matrix Multiplication Interpretation of Relation Composition
Let $A$, $B$ and $C$ be finite non-empty sets that are initial segments of $\N_{\ne 0}$. Let $\RR \subseteq B \times A$ and $\SS \subseteq C \times B$ be relations. Let $\mathbf R$ and $\mathbf S$ be matrices which we define as follows: :$\sqbrk r_{i j} = \begin{cases} \T & : \tuple {i, j} \in \RR \\ \F & : \tuple {i, ...
=== Sufficient Condition === Suppose for some $i, j$: :$\sqbrk {r s}_{i j} = \T$ Then by definition of $\lor$ there must exist some $k$ for which: :$\sqbrk r_{i k} \land \sqbrk s_{k j} = \T$ which by our definition implies: :$\tuple {i, k} \in \RR$ :$\tuple {k, j} \in \SS$ Then by definition of a composite relation: :$...
Let $A$, $B$ and $C$ be [[Definition:Finite Set|finite]] [[Definition:Non-Empty Set|non-empty]] [[Definition:Set|sets]] that are [[Definition:Initial Segment|initial segments]] of $\N_{\ne 0}$. Let $\RR \subseteq B \times A$ and $\SS \subseteq C \times B$ be [[Definition:Relation|relations]]. Let $\mathbf R$ and $\ma...
=== Sufficient Condition === Suppose for some $i, j$: :$\sqbrk {r s}_{i j} = \T$ Then by definition of $\lor$ there must exist some $k$ for which: :$\sqbrk r_{i k} \land \sqbrk s_{k j} = \T$ which by our definition implies: :$\tuple {i, k} \in \RR$ :$\tuple {k, j} \in \SS$ Then by definition of a [[Definition:...
Matrix Multiplication Interpretation of Relation Composition
https://proofwiki.org/wiki/Matrix_Multiplication_Interpretation_of_Relation_Composition
https://proofwiki.org/wiki/Matrix_Multiplication_Interpretation_of_Relation_Composition
[ "Relation Theory" ]
[ "Definition:Finite Set", "Definition:Non-Empty Set", "Definition:Set", "Definition:Initial Segment", "Definition:Relation", "Definition:Matrix", "Definition:Matrix Product (Conventional)", "Definition:Composition of Relations", "Definition:Ring (Abstract Algebra)", "Definition:Matrix Product (Conv...
[ "Definition:Composition of Relations" ]
proofwiki-7252
Space is Compact iff Every Cover from Basis has Finite Subcover
Let $T = \struct {S, \tau}$ be a topological space. Let $\BB \subseteq \tau$ be a basis of $\tau$. Then $T = \struct {S, \tau}$ is '''compact''' {{iff}}: :from every cover of $S$ by elements of $\BB$, a finite subcover of $S$ can be selected.
=== Sufficient Condition === Let every open cover for $S$ have a finite subcover. Then every cover of $S$ by elements of $\BB$ is an open cover for $S$. So: :from every cover of $S$ by elements of $\BB$, a finite subcover of $S$ can be selected. {{qed|lemma}}
Let $T = \struct {S, \tau}$ be a [[Definition:Topological Space|topological space]]. Let $\BB \subseteq \tau$ be a [[Definition:Basis (Topology)|basis]] of $\tau$. Then $T = \struct {S, \tau}$ is '''[[Definition:Compact Topological Space|compact]]''' {{iff}}: :from every [[Definition:Cover of Set|cover]] of $S$ by [...
=== Sufficient Condition === Let every [[Definition:Open Cover|open cover]] for $S$ have a [[Definition:Finite Subcover|finite subcover]]. Then every [[Definition:Cover of Set|cover]] of $S$ by [[Definition:Element|elements]] of $\BB$ is an [[Definition:Open Cover|open cover]] for $S$. So: :from every [[Definition:C...
Space is Compact iff Every Cover from Basis has Finite Subcover
https://proofwiki.org/wiki/Space_is_Compact_iff_Every_Cover_from_Basis_has_Finite_Subcover
https://proofwiki.org/wiki/Space_is_Compact_iff_Every_Cover_from_Basis_has_Finite_Subcover
[ "Compact Topological Spaces", "Subcovers", "Topological Bases" ]
[ "Definition:Topological Space", "Definition:Basis (Topology)", "Definition:Compact Topological Space", "Definition:Cover of Set", "Definition:Element", "Definition:Subcover/Finite" ]
[ "Definition:Open Cover", "Definition:Subcover/Finite", "Definition:Cover of Set", "Definition:Element", "Definition:Open Cover", "Definition:Cover of Set", "Definition:Element", "Definition:Subcover/Finite", "Definition:Cover of Set", "Definition:Element", "Definition:Subcover/Finite", "Defini...
proofwiki-7253
Set of Subsets is Cover iff Set of Complements is Free
Let $S$ be a set. Let $\CC$ be a set of sets. Then $\CC$ is a cover for $S$ {{iff}} $\set {\relcomp S X: X \in \CC}$ is free.
Let $S$ be a set. Let us recall the definition of free: {{:Definition:Free Set of Sets}}
Let $S$ be a [[Definition:Set|set]]. Let $\CC$ be a [[Definition:Set of Sets|set of sets]]. Then $\CC$ is a [[Definition:Cover of Set|cover for $S$]] {{iff}} $\set {\relcomp S X: X \in \CC}$ is [[Definition:Free Set of Sets|free]].
Let $S$ be a [[Definition:Set|set]]. Let us recall the definition of [[Definition:Free Set of Sets|free]]: {{:Definition:Free Set of Sets}}
Set of Subsets is Cover iff Set of Complements is Free
https://proofwiki.org/wiki/Set_of_Subsets_is_Cover_iff_Set_of_Complements_is_Free
https://proofwiki.org/wiki/Set_of_Subsets_is_Cover_iff_Set_of_Complements_is_Free
[ "Set Theory" ]
[ "Definition:Set", "Definition:Set of Sets", "Definition:Cover of Set", "Definition:Free Set of Sets" ]
[ "Definition:Set", "Definition:Free Set of Sets", "Definition:Free Set of Sets", "Definition:Free Set of Sets", "Definition:Free Set of Sets" ]
proofwiki-7254
Conditional is Equivalent to Negation of Conjunction with Negative/Formulation 2/Reverse Implication
:$\vdash \paren {\neg \paren {p \land \neg q} } \implies \paren {p \implies q}$
{{BeginTableau|\vdash \paren {\neg \paren {p \land \neg q} } \implies \paren {p \implies q} }} {{Assumption|1|\neg \paren {p \land \neg q} }} {{SequentIntro|2|1|p \implies q|1|Conditional is Equivalent to Negation of Conjunction with Negative: Formulation 1}} {{Implication|3||\paren {\neg \paren {p \land \neg q} } \imp...
:$\vdash \paren {\neg \paren {p \land \neg q} } \implies \paren {p \implies q}$
{{BeginTableau|\vdash \paren {\neg \paren {p \land \neg q} } \implies \paren {p \implies q} }} {{Assumption|1|\neg \paren {p \land \neg q} }} {{SequentIntro|2|1|p \implies q|1|[[Conditional is Equivalent to Negation of Conjunction with Negative/Formulation 1/Reverse Implication|Conditional is Equivalent to Negation of ...
Conditional is Equivalent to Negation of Conjunction with Negative/Formulation 2/Reverse Implication
https://proofwiki.org/wiki/Conditional_is_Equivalent_to_Negation_of_Conjunction_with_Negative/Formulation_2/Reverse_Implication
https://proofwiki.org/wiki/Conditional_is_Equivalent_to_Negation_of_Conjunction_with_Negative/Formulation_2/Reverse_Implication
[ "Conditional is Equivalent to Negation of Conjunction with Negative" ]
[]
[ "Conditional is Equivalent to Negation of Conjunction with Negative/Formulation 1/Reverse Implication", "Category:Conditional is Equivalent to Negation of Conjunction with Negative" ]
proofwiki-7255
Biconditional Elimination
The '''rule of biconditional elimination''' is a valid argument in types of logic dealing with conditionals $\implies$ and biconditionals $\iff$. This includes classical propositional logic and predicate logic, and in particular natural deduction. === Proof Rule === {{:Biconditional Elimination/Proof Rule}} === Sequent...
=== Form 1 === {{:Biconditional Elimination/Sequent Form/Proof 1/Form 1}} === Form 2 === {{:Biconditional Elimination/Sequent Form/Proof 1/Form 2}}
The '''rule of [[Biconditional Elimination|biconditional elimination]]''' is a [[Definition:Valid Argument|valid argument]] in types of [[Definition:Logic|logic]] dealing with [[Definition:Conditional|conditionals]] $\implies$ and [[Definition:Biconditional|biconditionals]] $\iff$. This includes [[Definition:Classical...
=== [[Biconditional Elimination/Sequent Form/Proof 1/Form 1|Form 1]] === {{:Biconditional Elimination/Sequent Form/Proof 1/Form 1}} === [[Biconditional Elimination/Sequent Form/Proof 1/Form 2|Form 2]] === {{:Biconditional Elimination/Sequent Form/Proof 1/Form 2}}
Biconditional Elimination/Sequent Form/Proof 1
https://proofwiki.org/wiki/Biconditional_Elimination
https://proofwiki.org/wiki/Biconditional_Elimination/Sequent_Form/Proof_1
[ "Biconditional Elimination", "Biconditional", "Conditional" ]
[ "Biconditional Elimination", "Definition:Valid Argument", "Definition:Logic", "Definition:Conditional", "Definition:Biconditional", "Definition:Classical Propositional Logic", "Definition:Predicate Logic", "Definition:Natural Deduction", "Biconditional Elimination/Proof Rule", "Biconditional Elimi...
[ "Biconditional Elimination/Sequent Form/Proof 1/Form 1", "Biconditional Elimination/Sequent Form/Proof 1/Form 2" ]
proofwiki-7256
Biconditional Elimination
The '''rule of biconditional elimination''' is a valid argument in types of logic dealing with conditionals $\implies$ and biconditionals $\iff$. This includes classical propositional logic and predicate logic, and in particular natural deduction. === Proof Rule === {{:Biconditional Elimination/Proof Rule}} === Sequent...
We apply the Method of Truth Tables. $\begin{array}{|ccc||ccc|ccc|} \hline p & \iff & q & p & \implies & q & q & \implies & p \\ \hline \F & \T & \F & \F & \T & \F & \F & \T & \F \\ \F & \F & \T & \F & \T & \T & \T & \F & \F \\ \T & \F & \F & \T & \F & \F & \F & \T & \T \\ \T & \T & \T & \T & \F & \T & \T & \T & \T \\ ...
The '''rule of [[Biconditional Elimination|biconditional elimination]]''' is a [[Definition:Valid Argument|valid argument]] in types of [[Definition:Logic|logic]] dealing with [[Definition:Conditional|conditionals]] $\implies$ and [[Definition:Biconditional|biconditionals]] $\iff$. This includes [[Definition:Classical...
We apply the [[Method of Truth Tables]]. $\begin{array}{|ccc||ccc|ccc|} \hline p & \iff & q & p & \implies & q & q & \implies & p \\ \hline \F & \T & \F & \F & \T & \F & \F & \T & \F \\ \F & \F & \T & \F & \T & \T & \T & \F & \F \\ \T & \F & \F & \T & \F & \F & \F & \T & \T \\ \T & \T & \T & \T & \F & \T & \T & \T & \...
Biconditional Elimination/Sequent Form/Proof by Truth Table
https://proofwiki.org/wiki/Biconditional_Elimination
https://proofwiki.org/wiki/Biconditional_Elimination/Sequent_Form/Proof_by_Truth_Table
[ "Biconditional Elimination", "Biconditional", "Conditional" ]
[ "Biconditional Elimination", "Definition:Valid Argument", "Definition:Logic", "Definition:Conditional", "Definition:Biconditional", "Definition:Classical Propositional Logic", "Definition:Predicate Logic", "Definition:Natural Deduction", "Biconditional Elimination/Proof Rule", "Biconditional Elimi...
[ "Method of Truth Tables", "Definition:True" ]
proofwiki-7257
Biconditional Introduction/Sequent Form
{{begin-eqn}} {{eqn | l = p | o = \implies | r = q }} {{eqn | l = q | o = \implies | r = p }} {{eqn | ll= \vdash | l = p | o = \iff | r = q }} {{end-eqn}}
{{BeginTableau|p \implies q, q \implies p \vdash p \iff q}} {{Premise|1|p \implies q}} {{Premise|2|q \implies p}} {{BiconditionalIntro|3|1, 2|p \iff q|1|2}} {{EndTableau}} {{Qed}}
{{begin-eqn}} {{eqn | l = p | o = \implies | r = q }} {{eqn | l = q | o = \implies | r = p }} {{eqn | ll= \vdash | l = p | o = \iff | r = q }} {{end-eqn}}
{{BeginTableau|p \implies q, q \implies p \vdash p \iff q}} {{Premise|1|p \implies q}} {{Premise|2|q \implies p}} {{BiconditionalIntro|3|1, 2|p \iff q|1|2}} {{EndTableau}} {{Qed}}
Biconditional Introduction/Sequent Form/Proof 1
https://proofwiki.org/wiki/Biconditional_Introduction/Sequent_Form
https://proofwiki.org/wiki/Biconditional_Introduction/Sequent_Form/Proof_1
[ "Biconditional Introduction" ]
[]
[]
proofwiki-7258
Biconditional Introduction/Sequent Form
{{begin-eqn}} {{eqn | l = p | o = \implies | r = q }} {{eqn | l = q | o = \implies | r = p }} {{eqn | ll= \vdash | l = p | o = \iff | r = q }} {{end-eqn}}
We apply the Method of Truth Tables. :<nowiki>$\begin {array} {|ccccccc||ccc|} \hline (p & \implies & q) & \land & (q & \implies & p) & p & \iff & q\\ \hline \F & \T & \F & \T & \F & \T & \F & \F & \T & \F \\ \F & \T & \T & \F & \T & \F & \F & \F & \F & \T \\ \T & \F & \F & \F & \F & \T & \T & \T & \F & \F \\ \T & \T &...
{{begin-eqn}} {{eqn | l = p | o = \implies | r = q }} {{eqn | l = q | o = \implies | r = p }} {{eqn | ll= \vdash | l = p | o = \iff | r = q }} {{end-eqn}}
We apply the [[Method of Truth Tables]]. :<nowiki>$\begin {array} {|ccccccc||ccc|} \hline (p & \implies & q) & \land & (q & \implies & p) & p & \iff & q\\ \hline \F & \T & \F & \T & \F & \T & \F & \F & \T & \F \\ \F & \T & \T & \F & \T & \F & \F & \F & \F & \T \\ \T & \F & \F & \F & \F & \T & \T & \T & \F & \F \\ \T &...
Biconditional Introduction/Sequent Form/Proof by Truth Table
https://proofwiki.org/wiki/Biconditional_Introduction/Sequent_Form
https://proofwiki.org/wiki/Biconditional_Introduction/Sequent_Form/Proof_by_Truth_Table
[ "Biconditional Introduction" ]
[]
[ "Method of Truth Tables", "Definition:True" ]
proofwiki-7259
Biconditional Elimination/Sequent Form/Proof 1/Form 1
:$p \iff q \vdash p \implies q$
{{BeginTableau|p \iff q \vdash p \implies q}} {{Premise|1|p \iff q}} {{BiconditionalElimination|2|1|p \implies q|1|1}} {{EndTableau}} {{Qed}}
:$p \iff q \vdash p \implies q$
{{BeginTableau|p \iff q \vdash p \implies q}} {{Premise|1|p \iff q}} {{BiconditionalElimination|2|1|p \implies q|1|1}} {{EndTableau}} {{Qed}}
Biconditional Elimination/Sequent Form/Proof 1/Form 1
https://proofwiki.org/wiki/Biconditional_Elimination/Sequent_Form/Proof_1/Form_1
https://proofwiki.org/wiki/Biconditional_Elimination/Sequent_Form/Proof_1/Form_1
[ "Biconditional Elimination" ]
[]
[]
proofwiki-7260
Biconditional Elimination/Sequent Form/Proof 1/Form 2
:$p \iff q \vdash q \implies p$
{{BeginTableau|p \iff q \vdash q \implies p}} {{Premise|1|p \iff q}} {{BiconditionalElimination|2|1|q \implies p|1|2}} {{EndTableau}} {{Qed}}
:$p \iff q \vdash q \implies p$
{{BeginTableau|p \iff q \vdash q \implies p}} {{Premise|1|p \iff q}} {{BiconditionalElimination|2|1|q \implies p|1|2}} {{EndTableau}} {{Qed}}
Biconditional Elimination/Sequent Form/Proof 1/Form 2
https://proofwiki.org/wiki/Biconditional_Elimination/Sequent_Form/Proof_1/Form_2
https://proofwiki.org/wiki/Biconditional_Elimination/Sequent_Form/Proof_1/Form_2
[ "Biconditional Elimination" ]
[]
[]
proofwiki-7261
Biconditional is Commutative/Formulation 1/Proof 1
: $p \iff q \dashv \vdash q \iff p$
{{BeginTableau|p \iff q \vdash q \iff p}} {{Premise|1|p \iff q}} {{BiconditionalElimination|2|1|p \implies q|1|1}} {{BiconditionalElimination|3|1|q \implies p|1|2}} {{BiconditionalIntro|4|1|q \iff p|3|2}} {{EndTableau}} {{qed|lemma}} {{BeginTableau|q \iff p \vdash p \iff q}} {{Premise|1|q \iff p}} {{BiconditionalElimin...
: $p \iff q \dashv \vdash q \iff p$
{{BeginTableau|p \iff q \vdash q \iff p}} {{Premise|1|p \iff q}} {{BiconditionalElimination|2|1|p \implies q|1|1}} {{BiconditionalElimination|3|1|q \implies p|1|2}} {{BiconditionalIntro|4|1|q \iff p|3|2}} {{EndTableau}} {{qed|lemma}} {{BeginTableau|q \iff p \vdash p \iff q}} {{Premise|1|q \iff p}} {{BiconditionalElim...
Biconditional is Commutative/Formulation 1/Proof 1
https://proofwiki.org/wiki/Biconditional_is_Commutative/Formulation_1/Proof_1
https://proofwiki.org/wiki/Biconditional_is_Commutative/Formulation_1/Proof_1
[ "Biconditional is Commutative" ]
[]
[]
proofwiki-7262
Rule of Material Equivalence/Formulation 1
:$p \iff q \dashv \vdash \paren {p \implies q} \land \paren {q \implies p}$
{{BeginTableau|p \iff q \vdash \paren {p \implies q} \land \paren {q \implies p} }} {{Premise|1|p \iff q}} {{BiconditionalElimination|2|1|p \implies q|1|1}} {{BiconditionalElimination|3|1|q \implies p|1|2}} {{Conjunction|4|1|\paren {p \implies q} \land \paren {q \implies p}|2|3}} {{EndTableau}} {{BeginTableau|\paren {p...
:$p \iff q \dashv \vdash \paren {p \implies q} \land \paren {q \implies p}$
{{BeginTableau|p \iff q \vdash \paren {p \implies q} \land \paren {q \implies p} }} {{Premise|1|p \iff q}} {{BiconditionalElimination|2|1|p \implies q|1|1}} {{BiconditionalElimination|3|1|q \implies p|1|2}} {{Conjunction|4|1|\paren {p \implies q} \land \paren {q \implies p}|2|3}} {{EndTableau}} {{BeginTableau|\paren ...
Rule of Material Equivalence/Formulation 1/Proof 1
https://proofwiki.org/wiki/Rule_of_Material_Equivalence/Formulation_1
https://proofwiki.org/wiki/Rule_of_Material_Equivalence/Formulation_1/Proof_1
[ "Rule of Material Equivalence" ]
[]
[]
proofwiki-7263
Rule of Material Equivalence/Formulation 1
:$p \iff q \dashv \vdash \paren {p \implies q} \land \paren {q \implies p}$
We apply the Method of Truth Tables. As can be seen by inspection, the truth values under the main connectives match for all boolean interpretations. :<nowiki>$\begin{array}{|ccc|ccccccc|} \hline p & \iff & q & (p & \implies & q) & \land & (q & \implies & p) \\ \hline \F & \T & \F & \F & \T & \F & \T & \F & \T & \F \\ ...
:$p \iff q \dashv \vdash \paren {p \implies q} \land \paren {q \implies p}$
We apply the [[Method of Truth Tables]]. As can be seen by inspection, the [[Definition:Truth Value|truth values]] under the [[Definition:Main Connective (Propositional Logic)|main connectives]] match for all [[Definition:Boolean Interpretation|boolean interpretations]]. :<nowiki>$\begin{array}{|ccc|ccccccc|} \hline ...
Rule of Material Equivalence/Formulation 1/Proof by Truth Table
https://proofwiki.org/wiki/Rule_of_Material_Equivalence/Formulation_1
https://proofwiki.org/wiki/Rule_of_Material_Equivalence/Formulation_1/Proof_by_Truth_Table
[ "Rule of Material Equivalence" ]
[]
[ "Method of Truth Tables", "Definition:Truth Value", "Definition:Main Connective/Propositional Logic", "Definition:Boolean Interpretation" ]
proofwiki-7264
Equivalences are Interderivable/Forward Implication
: $\left ({p \dashv \vdash q}\right) \vdash \left ({p \iff q}\right)$
{{BeginTableau|\left({p \dashv \vdash q}\right) \vdash p \iff q}} {{Premise|1|p \dashv \vdash q}} {{SequentIntro|2|1|\left ({p \vdash q}\right) \land \left ({q \vdash p}\right)|1 |Definition of Interderivable}} {{Assumption|3|p}} {{Simplification|4|1, 3|p \vdash q|2|1}} {{Implication|5|1|p \implies q|3|4}} {{Assumpti...
: $\left ({p \dashv \vdash q}\right) \vdash \left ({p \iff q}\right)$
{{BeginTableau|\left({p \dashv \vdash q}\right) \vdash p \iff q}} {{Premise|1|p \dashv \vdash q}} {{SequentIntro|2|1|\left ({p \vdash q}\right) \land \left ({q \vdash p}\right)|1 |Definition of [[Definition:Interderivable|Interderivable]]}} {{Assumption|3|p}} {{Simplification|4|1, 3|p \vdash q|2|1}} {{Implication|5|1...
Equivalences are Interderivable/Forward Implication
https://proofwiki.org/wiki/Equivalences_are_Interderivable/Forward_Implication
https://proofwiki.org/wiki/Equivalences_are_Interderivable/Forward_Implication
[ "Equivalences are Interderivable" ]
[]
[ "Definition:Logical Equivalence", "Category:Equivalences are Interderivable" ]
proofwiki-7265
Equivalences are Interderivable/Reverse Implication
: $\left ({p \iff q}\right) \vdash \left ({p \dashv \vdash q}\right)$
{{BeginTableau|p \iff q \vdash \left({p \vdash q}\right)}} {{Premise|1|p \iff q}} {{BiconditionalElimination|3|1|p \implies q|1|1}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q|2|3}} {{EndTableau}} {{qed|lemma}} {{BeginTableau|p \iff q \vdash \left({q \vdash p}\right)}} {{Premise|1|p \iff q}} {{BiconditionalElimination|3|...
: $\left ({p \iff q}\right) \vdash \left ({p \dashv \vdash q}\right)$
{{BeginTableau|p \iff q \vdash \left({p \vdash q}\right)}} {{Premise|1|p \iff q}} {{BiconditionalElimination|3|1|p \implies q|1|1}} {{Assumption|3|p}} {{ModusPonens|4|1, 3|q|2|3}} {{EndTableau}} {{qed|lemma}} {{BeginTableau|p \iff q \vdash \left({q \vdash p}\right)}} {{Premise|1|p \iff q}} {{BiconditionalElimination|...
Equivalences are Interderivable/Reverse Implication
https://proofwiki.org/wiki/Equivalences_are_Interderivable/Reverse_Implication
https://proofwiki.org/wiki/Equivalences_are_Interderivable/Reverse_Implication
[ "Equivalences are Interderivable" ]
[]
[ "Category:Equivalences are Interderivable" ]
proofwiki-7266
Compact Subspace of Linearly Ordered Space/Reverse Implication
Let $\struct {X, \preceq, \tau}$ be a linearly ordered space. Let $Y \subseteq X$ be a non-empty subset of $X$. Let the following hold: :$(1): \quad$ For every non-empty $S \subseteq Y$, $S$ has a supremum and an infimum in $X$. :$(2): \quad$ For every non-empty $S \subseteq Y$: $\sup S, \inf S \in Y$. Then $Y$ is a co...
Let $\tau'$ be the $\tau$-relative subspace topology on $Y$. Let $\preceq'$ be the restriction of $\preceq$ to $Y$. === Lemma === {{:Compact Subspace of Linearly Ordered Space/Lemma 2}}{{qed|lemma}} The premises immediately show that $\struct {Y, \preceq'}$ is a complete lattice. By Complete Linearly Ordered Space is C...
Let $\struct {X, \preceq, \tau}$ be a [[Definition:Linearly Ordered Space|linearly ordered space]]. Let $Y \subseteq X$ be a [[Definition:Non-Empty Set|non-empty]] [[Definition:Subset|subset]] of $X$. Let the following hold: :$(1): \quad$ For every [[Definition:Non-Empty Set|non-empty]] $S \subseteq Y$, $S$ has a [[...
Let $\tau'$ be the $\tau$-relative [[Definition:Subspace Topology|subspace topology]] on $Y$. Let $\preceq'$ be the [[Definition:Restriction of Ordering|restriction]] of $\preceq$ to $Y$. === [[Compact Subspace of Linearly Ordered Space/Lemma 2|Lemma]] === {{:Compact Subspace of Linearly Ordered Space/Lemma 2}}{{qed...
Compact Subspace of Linearly Ordered Space/Reverse Implication/Proof 1
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space/Reverse_Implication
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space/Reverse_Implication/Proof_1
[ "Compact Subspace of Linearly Ordered Space" ]
[ "Definition:Linearly Ordered Space", "Definition:Non-Empty Set", "Definition:Subset", "Definition:Non-Empty Set", "Definition:Supremum of Set", "Definition:Infimum of Set", "Definition:Non-Empty Set", "Definition:Compact Topological Space/Subspace" ]
[ "Definition:Topological Subspace", "Definition:Restriction of Ordering", "Compact Subspace of Linearly Ordered Space/Lemma 2", "Definition:Complete Lattice", "Complete Linearly Ordered Space is Compact", "Definition:Compact Topological Space/Subspace" ]
proofwiki-7267
Compact Subspace of Linearly Ordered Space/Reverse Implication
Let $\struct {X, \preceq, \tau}$ be a linearly ordered space. Let $Y \subseteq X$ be a non-empty subset of $X$. Let the following hold: :$(1): \quad$ For every non-empty $S \subseteq Y$, $S$ has a supremum and an infimum in $X$. :$(2): \quad$ For every non-empty $S \subseteq Y$: $\sup S, \inf S \in Y$. Then $Y$ is a co...
Let $\FF$ be an ultrafilter on $Y$. For $S \in \FF$, let $\map f S = \inf S$. Let $p = \sup \map f \FF$. {{improve|perhaps directly use $p :{{=}} \ds \sup_{S \mathop \in \FF} \inf S$?}} Then $\FF$ converges to $p$: === Upward rays === Let $a \in X$ with $a \prec p$. Since $\FF$ is an ultrafilter, either $Y \cap {\uparr...
Let $\struct {X, \preceq, \tau}$ be a [[Definition:Linearly Ordered Space|linearly ordered space]]. Let $Y \subseteq X$ be a [[Definition:Non-Empty Set|non-empty]] [[Definition:Subset|subset]] of $X$. Let the following hold: :$(1): \quad$ For every [[Definition:Non-Empty Set|non-empty]] $S \subseteq Y$, $S$ has a [[...
Let $\FF$ be an [[Definition:Ultrafilter on Set|ultrafilter]] on $Y$. For $S \in \FF$, let $\map f S = \inf S$. Let $p = \sup \map f \FF$. {{improve|perhaps directly use $p :{{=}} \ds \sup_{S \mathop \in \FF} \inf S$?}} Then $\FF$ converges to $p$: === Upward rays === Let $a \in X$ with $a \prec p$. Since $\FF$ ...
Compact Subspace of Linearly Ordered Space/Reverse Implication/Proof 2
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space/Reverse_Implication
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space/Reverse_Implication/Proof_2
[ "Compact Subspace of Linearly Ordered Space" ]
[ "Definition:Linearly Ordered Space", "Definition:Non-Empty Set", "Definition:Subset", "Definition:Non-Empty Set", "Definition:Supremum of Set", "Definition:Infimum of Set", "Definition:Non-Empty Set", "Definition:Compact Topological Space/Subspace" ]
[ "Definition:Ultrafilter on Set", "Definition:Ultrafilter on Set", "Definition:Filter on Set", "Definition:Supremum of Set", "Definition:Infimum of Set", "Definition:Contradiction", "Definition:Lower Bound of Set", "Definition:Infimum of Set", "Extended Transitivity", "Definition:Supremum of Set", ...
proofwiki-7268
Modus Ponendo Tollens/Sequent Form/Case 1
:$\neg \paren {p \land q}, p \vdash \neg q$
{{BeginTableau|\neg \paren {p \land q}, p \vdash \neg q}} {{Premise|1|\neg \paren {p \land q} }} {{Premise|2|p}} {{Assumption|3|q}} {{Conjunction|4|2, 3|p \land q|2|3}} {{NonContradiction|5|1, 2, 3|4|1}} {{Contradiction|6|1, 2|\neg q|3|5}} {{EndTableau|qed}}
:$\neg \paren {p \land q}, p \vdash \neg q$
{{BeginTableau|\neg \paren {p \land q}, p \vdash \neg q}} {{Premise|1|\neg \paren {p \land q} }} {{Premise|2|p}} {{Assumption|3|q}} {{Conjunction|4|2, 3|p \land q|2|3}} {{NonContradiction|5|1, 2, 3|4|1}} {{Contradiction|6|1, 2|\neg q|3|5}} {{EndTableau|qed}}
Modus Ponendo Tollens/Sequent Form/Case 1
https://proofwiki.org/wiki/Modus_Ponendo_Tollens/Sequent_Form/Case_1
https://proofwiki.org/wiki/Modus_Ponendo_Tollens/Sequent_Form/Case_1
[ "Modus Ponendo Tollens" ]
[]
[]
proofwiki-7269
Modus Ponendo Tollens/Sequent Form/Case 2
:$\neg \left({p \land q}\right), q \vdash \neg p$
{{BeginTableau|\neg \left({p \land q}\right), q \vdash \neg p}} {{Premise|1|\neg \left({p \land q}\right)}} {{Premise|2|q}} {{Assumption|3|p}} {{Conjunction|4|2, 3|p \land q|3|2}} {{NonContradiction|5|1, 2, 3|4|1}} {{Contradiction|6|1, 2|\neg p|3|5}} {{EndTableau}} {{qed}} Category:Modus Ponendo Tollens mjeey35ngrumpe2...
:$\neg \left({p \land q}\right), q \vdash \neg p$
{{BeginTableau|\neg \left({p \land q}\right), q \vdash \neg p}} {{Premise|1|\neg \left({p \land q}\right)}} {{Premise|2|q}} {{Assumption|3|p}} {{Conjunction|4|2, 3|p \land q|3|2}} {{NonContradiction|5|1, 2, 3|4|1}} {{Contradiction|6|1, 2|\neg p|3|5}} {{EndTableau}} {{qed}} [[Category:Modus Ponendo Tollens]] mjeey35ngr...
Modus Ponendo Tollens/Sequent Form/Case 2
https://proofwiki.org/wiki/Modus_Ponendo_Tollens/Sequent_Form/Case_2
https://proofwiki.org/wiki/Modus_Ponendo_Tollens/Sequent_Form/Case_2
[ "Modus Ponendo Tollens" ]
[]
[ "Category:Modus Ponendo Tollens" ]
proofwiki-7270
Union of Subsets is Subset/Subset of Power Set
Let $S$ and $T$ be sets. Let $\powerset S$ be the power set of $S$. Let $\mathbb S$ be a subset of $\powerset S$. Then: :$\ds \paren {\forall X \in \mathbb S: X \subseteq T} \implies \bigcup \mathbb S \subseteq T$
Let $\mathbb S \subseteq \powerset S$. Suppose that $\forall X \in \mathbb S: X \subseteq T$. Consider any $\ds x \in \bigcup \mathbb S$. By definition of set union, it follows that: :$\exists X \in \mathbb S: x \in X$ But as $X \subseteq T$ it follows that $x \in T$. Thus it follows that: :$\ds \bigcup \mathbb S \subs...
Let $S$ and $T$ be [[Definition:Set|sets]]. Let $\powerset S$ be the [[Definition:Power Set|power set]] of $S$. Let $\mathbb S$ be a [[Definition:Subset|subset]] of $\powerset S$. Then: :$\ds \paren {\forall X \in \mathbb S: X \subseteq T} \implies \bigcup \mathbb S \subseteq T$
Let $\mathbb S \subseteq \powerset S$. Suppose that $\forall X \in \mathbb S: X \subseteq T$. Consider any $\ds x \in \bigcup \mathbb S$. By definition of [[Definition:Set Union|set union]], it follows that: :$\exists X \in \mathbb S: x \in X$ But as $X \subseteq T$ it follows that $x \in T$. Thus it follows that:...
Union of Subsets is Subset/Subset of Power Set
https://proofwiki.org/wiki/Union_of_Subsets_is_Subset/Subset_of_Power_Set
https://proofwiki.org/wiki/Union_of_Subsets_is_Subset/Subset_of_Power_Set
[ "Set Union", "Subsets" ]
[ "Definition:Set", "Definition:Power Set", "Definition:Subset" ]
[ "Definition:Set Union", "Category:Set Union", "Category:Subsets" ]
proofwiki-7271
Conjunction with Negative is Equivalent to Negation of Conditional/Formulation 2/Forward Implication
:$\vdash \paren {p \land \neg q} \implies \paren {\neg \paren {p \implies q} }$
{{BeginTableau|\vdash \paren {p \land \neg q} \implies \paren {\neg \paren {p \implies q} } }} {{Assumption|1|p \land \neg q}} {{Assumption|2|p \implies q| Assume the opposite of what is to be proved ...}} {{Simplification|3|1|p|1|1}} {{Simplification|4|1|\neg q|1|2}} {{ModusPonens|5|1, 2|q|2|3}} {{NonContradiction|6|1...
:$\vdash \paren {p \land \neg q} \implies \paren {\neg \paren {p \implies q} }$
{{BeginTableau|\vdash \paren {p \land \neg q} \implies \paren {\neg \paren {p \implies q} } }} {{Assumption|1|p \land \neg q}} {{Assumption|2|p \implies q| Assume the opposite of what is to be proved ...}} {{Simplification|3|1|p|1|1}} {{Simplification|4|1|\neg q|1|2}} {{ModusPonens|5|1, 2|q|2|3}} {{NonContradiction|6|1...
Conjunction with Negative is Equivalent to Negation of Conditional/Formulation 2/Forward Implication/Proof 1
https://proofwiki.org/wiki/Conjunction_with_Negative_is_Equivalent_to_Negation_of_Conditional/Formulation_2/Forward_Implication
https://proofwiki.org/wiki/Conjunction_with_Negative_is_Equivalent_to_Negation_of_Conditional/Formulation_2/Forward_Implication/Proof_1
[ "Conjunction with Negative is Equivalent to Negation of Conditional" ]
[]
[]
proofwiki-7272
Conjunction with Negative is Equivalent to Negation of Conditional/Formulation 2/Reverse Implication
:$\vdash \paren {\neg \paren {p \implies q} } \implies \paren {p \land \neg q}$
{{BeginTableau|\vdash \paren {\neg \paren {p \implies q} } \implies \paren {p \land \neg q} }} {{Assumption|1|\neg \paren {p \implies q} }} {{Assumption|2|\neg \paren {p \land \neg q} }} {{SequentIntro|3|2|p \implies q|2|Conditional is Equivalent to Negation of Conjunction with Negative}} {{NonContradiction|4|1, 2|3|1}...
:$\vdash \paren {\neg \paren {p \implies q} } \implies \paren {p \land \neg q}$
{{BeginTableau|\vdash \paren {\neg \paren {p \implies q} } \implies \paren {p \land \neg q} }} {{Assumption|1|\neg \paren {p \implies q} }} {{Assumption|2|\neg \paren {p \land \neg q} }} {{SequentIntro|3|2|p \implies q|2|[[Conditional is Equivalent to Negation of Conjunction with Negative]]}} {{NonContradiction|4|1, 2|...
Conjunction with Negative is Equivalent to Negation of Conditional/Formulation 2/Reverse Implication/Proof 1
https://proofwiki.org/wiki/Conjunction_with_Negative_is_Equivalent_to_Negation_of_Conditional/Formulation_2/Reverse_Implication
https://proofwiki.org/wiki/Conjunction_with_Negative_is_Equivalent_to_Negation_of_Conditional/Formulation_2/Reverse_Implication/Proof_1
[ "Conjunction with Negative is Equivalent to Negation of Conditional" ]
[]
[ "Conditional is Equivalent to Negation of Conjunction with Negative" ]
proofwiki-7273
Conjunction with Negative is Equivalent to Negation of Conditional/Formulation 2/Reverse Implication
:$\vdash \paren {\neg \paren {p \implies q} } \implies \paren {p \land \neg q}$
{{BeginTableau|\vdash \paren {\neg \paren {p \implies q} } \implies \paren {p \land \neg q} }} {{Assumption|1|\neg \paren {p \implies q} }} {{SequentIntro|2|1|p \land \neg q|1|Conjunction with Negative is Equivalent to Negation of Conditional: Formulation 1: Reverse Implication}} {{Implication|3||\paren {\neg \paren {p...
:$\vdash \paren {\neg \paren {p \implies q} } \implies \paren {p \land \neg q}$
{{BeginTableau|\vdash \paren {\neg \paren {p \implies q} } \implies \paren {p \land \neg q} }} {{Assumption|1|\neg \paren {p \implies q} }} {{SequentIntro|2|1|p \land \neg q|1|[[Conjunction with Negative is Equivalent to Negation of Conditional/Formulation 1/Reverse Implication|Conjunction with Negative is Equivalent t...
Conjunction with Negative is Equivalent to Negation of Conditional/Formulation 2/Reverse Implication/Proof 2
https://proofwiki.org/wiki/Conjunction_with_Negative_is_Equivalent_to_Negation_of_Conditional/Formulation_2/Reverse_Implication
https://proofwiki.org/wiki/Conjunction_with_Negative_is_Equivalent_to_Negation_of_Conditional/Formulation_2/Reverse_Implication/Proof_2
[ "Conjunction with Negative is Equivalent to Negation of Conditional" ]
[]
[ "Conjunction with Negative is Equivalent to Negation of Conditional/Formulation 1/Reverse Implication" ]
proofwiki-7274
Convex Set is Star Convex Set
Let $V$ be a vector space over $\R$ or $\C$. Let $A \subseteq V$ be a non-empty convex set. Then $A$ is a star convex set, and every point in $A$ is a star center.
Let $a \in A$. Note that there is at least one point in $A$, as $A$ is non-empty. If $x \in A$, then there is a line segment joining $a$ and $x$. By definition, it follows that $A$ is star convex, and $a$ is a star center. {{qed}} Category:Convex Sets (Vector Spaces) bnnv4ei5bq7etdgcg2soj8upxict53j
Let $V$ be a [[Definition:Vector Space|vector space]] over $\R$ or $\C$. Let $A \subseteq V$ be a [[Definition:Empty Set|non-empty]] [[Definition:Convex Set (Vector Space)|convex set]]. Then $A$ is a [[Definition:Star Convex Set|star convex set]], and every point in $A$ is a [[Definition:Star Convex Set|star center]...
Let $a \in A$. Note that there is at least one point in $A$, as $A$ is [[Definition:Empty Set|non-empty]]. If $x \in A$, then there is a [[Definition:Straight Line Segment (Vector Space)|line segment]] joining $a$ and $x$. By definition, it follows that $A$ is [[Definition:Star Convex Set|star convex]], and $a$ is a...
Convex Set is Star Convex Set
https://proofwiki.org/wiki/Convex_Set_is_Star_Convex_Set
https://proofwiki.org/wiki/Convex_Set_is_Star_Convex_Set
[ "Convex Sets (Vector Spaces)" ]
[ "Definition:Vector Space", "Definition:Empty Set", "Definition:Convex Set (Vector Space)", "Definition:Star Convex Set", "Definition:Star Convex Set" ]
[ "Definition:Empty Set", "Definition:Convex Set (Vector Space)/Line Segment", "Definition:Star Convex Set", "Definition:Star Convex Set", "Category:Convex Sets (Vector Spaces)" ]
proofwiki-7275
Negation implies Negation of Conjunction/Case 1
:$\neg p \implies \neg \paren {p \land q}$
{{BeginTableau|\neg p \implies \neg \paren {p \land q} }} {{Assumption|1|\neg p}} {{Assumption|2|p \land q}} {{Simplification|3|2|p|2|1}} {{NonContradiction|4|1, 2|3|1}} {{Contradiction|5|1|\neg \paren {p \land q}|2|4}} {{Implication|6||\neg p \implies \neg \paren {p \land q}|1|5}} {{EndTableau|qed}}
:$\neg p \implies \neg \paren {p \land q}$
{{BeginTableau|\neg p \implies \neg \paren {p \land q} }} {{Assumption|1|\neg p}} {{Assumption|2|p \land q}} {{Simplification|3|2|p|2|1}} {{NonContradiction|4|1, 2|3|1}} {{Contradiction|5|1|\neg \paren {p \land q}|2|4}} {{Implication|6||\neg p \implies \neg \paren {p \land q}|1|5}} {{EndTableau|qed}}
Negation implies Negation of Conjunction/Case 1
https://proofwiki.org/wiki/Negation_implies_Negation_of_Conjunction/Case_1
https://proofwiki.org/wiki/Negation_implies_Negation_of_Conjunction/Case_1
[ "Negation implies Negation of Conjunction" ]
[]
[]
proofwiki-7276
Negation implies Negation of Conjunction/Case 2
:$\neg q \implies \neg \paren {p \land q}$
{{BeginTableau|\neg q \implies \neg \paren {p \land q} }} {{Assumption|1|\neg q}} {{Assumption|2|p \land q}} {{Simplification|3|2|q|2|2}} {{NonContradiction|4|1, 2|3|1}} {{Contradiction|5|1|\neg \paren {p \land q}|2|4}} {{Implication|6||\neg q \implies \neg \paren {p \land q}|1|5}} {{EndTableau|qed}}
:$\neg q \implies \neg \paren {p \land q}$
{{BeginTableau|\neg q \implies \neg \paren {p \land q} }} {{Assumption|1|\neg q}} {{Assumption|2|p \land q}} {{Simplification|3|2|q|2|2}} {{NonContradiction|4|1, 2|3|1}} {{Contradiction|5|1|\neg \paren {p \land q}|2|4}} {{Implication|6||\neg q \implies \neg \paren {p \land q}|1|5}} {{EndTableau|qed}}
Negation implies Negation of Conjunction/Case 2/Proof
https://proofwiki.org/wiki/Negation_implies_Negation_of_Conjunction/Case_2
https://proofwiki.org/wiki/Negation_implies_Negation_of_Conjunction/Case_2/Proof
[ "Negation implies Negation of Conjunction" ]
[]
[]
proofwiki-7277
Neighborhood Sub-Basis Criterion for Filter Convergence
Let $\struct {S, \tau}$ be a topological space. Let $\FF$ be a filter on $S$. Let $p \in S$. Then $\FF$ converges to $p$ {{iff}} $\FF$ contains as a subset a neighborhood sub-basis at $p$.
=== Sufficient Condition === Let $\FF$ converges to $p$. Then it contains ''every'' neighborhood of $p$. The set of neighborhoods of $p$ is trivially a neighborhood sub-basis at $p$. {{qed|lemma}}
Let $\struct {S, \tau}$ be a [[Definition:Topological Space|topological space]]. Let $\FF$ be a [[Definition:Filter on Set|filter]] on $S$. Let $p \in S$. Then $\FF$ [[Definition:Convergent Filter|converges]] to $p$ {{iff}} $\FF$ contains as a [[Definition:Subset|subset]] a [[Definition:Neighborhood Sub-Basis|neigh...
=== Sufficient Condition === Let $\FF$ [[Definition:Convergent Filter|converges]] to $p$. Then it contains ''every'' [[Definition:Neighborhood of Point|neighborhood]] of $p$. The set of [[Definition:Neighborhood of Point|neighborhoods]] of $p$ is trivially a [[Definition:Neighborhood Sub-Basis|neighborhood sub-basis...
Neighborhood Sub-Basis Criterion for Filter Convergence
https://proofwiki.org/wiki/Neighborhood_Sub-Basis_Criterion_for_Filter_Convergence
https://proofwiki.org/wiki/Neighborhood_Sub-Basis_Criterion_for_Filter_Convergence
[ "Filter Theory", "Topological Bases" ]
[ "Definition:Topological Space", "Definition:Filter on Set", "Definition:Convergent Filter", "Definition:Subset", "Definition:Neighborhood Sub-Basis" ]
[ "Definition:Convergent Filter", "Definition:Neighborhood (Topology)/Point", "Definition:Neighborhood (Topology)/Point", "Definition:Neighborhood Sub-Basis", "Definition:Neighborhood Sub-Basis", "Definition:Neighborhood (Topology)/Point", "Definition:Neighborhood Sub-Basis", "Definition:Neighborhood (T...
proofwiki-7278
Rule of Material Implication/Formulation 2/Forward Implication
: $\vdash \left({p \implies q}\right) \implies \left({\neg p \lor q}\right)$
{{BeginTableau|\left({p \implies q}\right) \implies \left({\neg p \lor q}\right)}} {{Assumption|1|p \implies q}} {{SequentIntro|2|1|\neg p \lor q|1|Rule of Material Implication: Formulation 1}} {{Implication|3||\left({p \implies q}\right) \implies \left({\neg p \lor q}\right)|1|2}} {{EndTableau}} {{qed}} {{LEM|Rule of ...
: $\vdash \left({p \implies q}\right) \implies \left({\neg p \lor q}\right)$
{{BeginTableau|\left({p \implies q}\right) \implies \left({\neg p \lor q}\right)}} {{Assumption|1|p \implies q}} {{SequentIntro|2|1|\neg p \lor q|1|[[Rule of Material Implication/Formulation 1/Forward Implication|Rule of Material Implication: Formulation 1]]}} {{Implication|3||\left({p \implies q}\right) \implies \left...
Rule of Material Implication/Formulation 2/Forward Implication
https://proofwiki.org/wiki/Rule_of_Material_Implication/Formulation_2/Forward_Implication
https://proofwiki.org/wiki/Rule_of_Material_Implication/Formulation_2/Forward_Implication
[ "Rule of Material Implication" ]
[]
[ "Rule of Material Implication/Formulation 1/Forward Implication" ]
proofwiki-7279
Rule of Material Implication/Formulation 2/Reverse Implication
:$\vdash \paren {\neg p \lor q} \implies \paren {p \implies q}$
{{BeginTableau|\paren {\neg p \lor q} \implies \paren {p \implies q} }} {{Assumption|1|\neg p \lor q}} {{SequentIntro|2|1|p \implies q|1|Rule of Material Implication: Formulation 1}} {{Implication|3||\paren {\neg p \lor q} \implies \paren {p \implies q}|1|2}} {{EndTableau}} {{qed}}
:$\vdash \paren {\neg p \lor q} \implies \paren {p \implies q}$
{{BeginTableau|\paren {\neg p \lor q} \implies \paren {p \implies q} }} {{Assumption|1|\neg p \lor q}} {{SequentIntro|2|1|p \implies q|1|[[Rule of Material Implication/Formulation 1/Reverse Implication|Rule of Material Implication: Formulation 1]]}} {{Implication|3||\paren {\neg p \lor q} \implies \paren {p \implies q}...
Rule of Material Implication/Formulation 2/Reverse Implication
https://proofwiki.org/wiki/Rule_of_Material_Implication/Formulation_2/Reverse_Implication
https://proofwiki.org/wiki/Rule_of_Material_Implication/Formulation_2/Reverse_Implication
[ "Rule of Material Implication" ]
[]
[ "Rule of Material Implication/Formulation 1/Reverse Implication" ]
proofwiki-7280
Compact Subspace of Linearly Ordered Space
Let $\struct {X, \preceq, \tau}$ be a linearly ordered space. Let $Y \subseteq X$ be a non-empty subset of $X$. Then $Y$ is a compact subspace of $\struct {X, \tau}$ {{iff}} both of the following hold: :$(1): \quad$ For every non-empty $S \subseteq Y$, $S$ has a supremum and an infimum in $X$. :$(2): \quad$ For every n...
=== Forward Implication === Let $S$ be a non-empty subset of $Y$. By Compact Subspace of Linearly Ordered Space: Lemma 1, $S$ has a supremum $k$ in $Y$. {{explain|The lemma shows that the structure in question is a complete lattice. Take that further step to assert the existence of the supremum.}} {{explain|supremum WR...
Let $\struct {X, \preceq, \tau}$ be a [[Definition:Linearly Ordered Space|linearly ordered space]]. Let $Y \subseteq X$ be a [[Definition:Non-Empty Set|non-empty]] [[Definition:Subset|subset]] of $X$. Then $Y$ is a [[Definition:Compact Subspace|compact subspace]] of $\struct {X, \tau}$ {{iff}} both of the following ...
=== Forward Implication === Let $S$ be a [[Definition:Non-Empty Set|non-empty]] [[Definition:Subset|subset]] of $Y$. By [[Compact Subspace of Linearly Ordered Space/Lemma 1|Compact Subspace of Linearly Ordered Space: Lemma 1]], $S$ has a [[Definition:Supremum of Set|supremum]] $k$ in $Y$. {{explain|The lemma shows t...
Compact Subspace of Linearly Ordered Space
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space
[ "Compact Subspace of Linearly Ordered Space", "Linearly Ordered Spaces", "Compact Topological Spaces" ]
[ "Definition:Linearly Ordered Space", "Definition:Non-Empty Set", "Definition:Subset", "Definition:Compact Topological Space/Subspace", "Definition:Non-Empty Set", "Definition:Supremum of Set", "Definition:Infimum of Set", "Definition:Non-Empty Set" ]
[ "Definition:Non-Empty Set", "Definition:Subset", "Compact Subspace of Linearly Ordered Space/Lemma 1", "Definition:Supremum of Set", "Definition:Upper Bound of Set", "Definition:Lower Closure/Element", "Definition:Upper Closure/Element", "Definition:Open Cover", "Definition:Subcover/Finite", "Defi...
proofwiki-7281
Compact Subspace of Linearly Ordered Space
Let $\struct {X, \preceq, \tau}$ be a linearly ordered space. Let $Y \subseteq X$ be a non-empty subset of $X$. Then $Y$ is a compact subspace of $\struct {X, \tau}$ {{iff}} both of the following hold: :$(1): \quad$ For every non-empty $S \subseteq Y$, $S$ has a supremum and an infimum in $X$. :$(2): \quad$ For every n...
Let $\tau'$ be the $\tau$-relative subspace topology on $Y$. Let $\preceq'$ be the restriction of $\preceq$ to $Y$. === Lemma === {{:Compact Subspace of Linearly Ordered Space/Lemma 2}}{{qed|lemma}} The premises immediately show that $\struct {Y, \preceq'}$ is a complete lattice. By Complete Linearly Ordered Space is C...
Let $\struct {X, \preceq, \tau}$ be a [[Definition:Linearly Ordered Space|linearly ordered space]]. Let $Y \subseteq X$ be a [[Definition:Non-Empty Set|non-empty]] [[Definition:Subset|subset]] of $X$. Then $Y$ is a [[Definition:Compact Subspace|compact subspace]] of $\struct {X, \tau}$ {{iff}} both of the following ...
Let $\tau'$ be the $\tau$-relative [[Definition:Subspace Topology|subspace topology]] on $Y$. Let $\preceq'$ be the [[Definition:Restriction of Ordering|restriction]] of $\preceq$ to $Y$. === [[Compact Subspace of Linearly Ordered Space/Lemma 2|Lemma]] === {{:Compact Subspace of Linearly Ordered Space/Lemma 2}}{{qed...
Compact Subspace of Linearly Ordered Space/Reverse Implication/Proof 1
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space/Reverse_Implication/Proof_1
[ "Compact Subspace of Linearly Ordered Space", "Linearly Ordered Spaces", "Compact Topological Spaces" ]
[ "Definition:Linearly Ordered Space", "Definition:Non-Empty Set", "Definition:Subset", "Definition:Compact Topological Space/Subspace", "Definition:Non-Empty Set", "Definition:Supremum of Set", "Definition:Infimum of Set", "Definition:Non-Empty Set" ]
[ "Definition:Topological Subspace", "Definition:Restriction of Ordering", "Compact Subspace of Linearly Ordered Space/Lemma 2", "Definition:Complete Lattice", "Complete Linearly Ordered Space is Compact", "Definition:Compact Topological Space/Subspace" ]
proofwiki-7282
Compact Subspace of Linearly Ordered Space
Let $\struct {X, \preceq, \tau}$ be a linearly ordered space. Let $Y \subseteq X$ be a non-empty subset of $X$. Then $Y$ is a compact subspace of $\struct {X, \tau}$ {{iff}} both of the following hold: :$(1): \quad$ For every non-empty $S \subseteq Y$, $S$ has a supremum and an infimum in $X$. :$(2): \quad$ For every n...
Let $\FF$ be an ultrafilter on $Y$. For $S \in \FF$, let $\map f S = \inf S$. Let $p = \sup \map f \FF$. {{improve|perhaps directly use $p :{{=}} \ds \sup_{S \mathop \in \FF} \inf S$?}} Then $\FF$ converges to $p$: === Upward rays === Let $a \in X$ with $a \prec p$. Since $\FF$ is an ultrafilter, either $Y \cap {\uparr...
Let $\struct {X, \preceq, \tau}$ be a [[Definition:Linearly Ordered Space|linearly ordered space]]. Let $Y \subseteq X$ be a [[Definition:Non-Empty Set|non-empty]] [[Definition:Subset|subset]] of $X$. Then $Y$ is a [[Definition:Compact Subspace|compact subspace]] of $\struct {X, \tau}$ {{iff}} both of the following ...
Let $\FF$ be an [[Definition:Ultrafilter on Set|ultrafilter]] on $Y$. For $S \in \FF$, let $\map f S = \inf S$. Let $p = \sup \map f \FF$. {{improve|perhaps directly use $p :{{=}} \ds \sup_{S \mathop \in \FF} \inf S$?}} Then $\FF$ converges to $p$: === Upward rays === Let $a \in X$ with $a \prec p$. Since $\FF$ ...
Compact Subspace of Linearly Ordered Space/Reverse Implication/Proof 2
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space
https://proofwiki.org/wiki/Compact_Subspace_of_Linearly_Ordered_Space/Reverse_Implication/Proof_2
[ "Compact Subspace of Linearly Ordered Space", "Linearly Ordered Spaces", "Compact Topological Spaces" ]
[ "Definition:Linearly Ordered Space", "Definition:Non-Empty Set", "Definition:Subset", "Definition:Compact Topological Space/Subspace", "Definition:Non-Empty Set", "Definition:Supremum of Set", "Definition:Infimum of Set", "Definition:Non-Empty Set" ]
[ "Definition:Ultrafilter on Set", "Definition:Ultrafilter on Set", "Definition:Filter on Set", "Definition:Supremum of Set", "Definition:Infimum of Set", "Definition:Contradiction", "Definition:Lower Bound of Set", "Definition:Infimum of Set", "Extended Transitivity", "Definition:Supremum of Set", ...
proofwiki-7283
Linearly Ordered Space is Hausdorff
Let $\struct {X, \preceq, \tau}$ be a linearly ordered space. Then $\struct {X, \tau}$ is a Hausdorff space.
Let $x, y \in X$ with $x \ne y$. Since $\le$ is a total ordering, either $x \prec y$ or $y \prec x$. {{WLOG}}, assume that $x \prec y$. If there is a $z \in X$ such that $x \prec z \prec y$, then $z^\prec$ and $z^\succ$ separate $x$ and $y$. Otherwise, by Upper Closure is Strict Upper Closure of Immediate Predecessor, ...
Let $\struct {X, \preceq, \tau}$ be a [[Definition:Linearly Ordered Space|linearly ordered space]]. Then $\struct {X, \tau}$ is a [[Definition:Hausdorff Space|Hausdorff space]].
Let $x, y \in X$ with $x \ne y$. Since $\le$ is a [[Definition:Total Ordering|total ordering]], either $x \prec y$ or $y \prec x$. {{WLOG}}, assume that $x \prec y$. If there is a $z \in X$ such that $x \prec z \prec y$, then $z^\prec$ and $z^\succ$ separate $x$ and $y$. Otherwise, by [[Upper Closure is Strict Upp...
Linearly Ordered Space is Hausdorff
https://proofwiki.org/wiki/Linearly_Ordered_Space_is_Hausdorff
https://proofwiki.org/wiki/Linearly_Ordered_Space_is_Hausdorff
[ "Linearly Ordered Spaces", "Examples of Hausdorff Spaces" ]
[ "Definition:Linearly Ordered Space", "Definition:T2 Space" ]
[ "Definition:Total Ordering", "Upper Closure is Strict Upper Closure of Immediate Predecessor", "Definition:T2 Space", "Category:Linearly Ordered Spaces", "Category:Examples of Hausdorff Spaces" ]
proofwiki-7284
Subset of Linearly Ordered Space which is Order-Complete and Closed but not Compact
Let $X = \hointr 0 1 \cup \openint 2 3 \cup \set 4$. Let $\preceq$ be the ordering on $X$ induced by the usual ordering of the real numbers. Let $\tau$ be the $\preceq$ order topology on $X$. Let $Y = \hointr 0 1 \cup \set 4$. Let $\tau'$ be the $\tau$-relative subspace topology on $Y$. Then: :$\struct {Y, \preceq}$ is...
First it is demonstrated that $\struct {Y, \preceq}$ is a complete lattice. Let $\phi: Y \to \closedint 0 1$ be defined as: :<nowiki>$\map \phi y = \begin{cases} y & : y \in \hointr 0 1 \\ 1 & : y = 4 \end{cases}$</nowiki> Then $\phi$ is a order isomorphism. {{explain|The above needs to be proved.}} {{qed|lemma}} We ha...
Let $X = \hointr 0 1 \cup \openint 2 3 \cup \set 4$. Let $\preceq$ be the [[Definition:Ordering|ordering]] on $X$ induced by the [[Definition:Usual Ordering|usual ordering]] of the [[Definition:Real Number|real numbers]]. Let $\tau$ be the $\preceq$ [[Definition:Order Topology|order topology]] on $X$. Let $Y = \hoin...
First it is demonstrated that $\struct {Y, \preceq}$ is a [[Definition:Complete Lattice|complete lattice]]. Let $\phi: Y \to \closedint 0 1$ be defined as: :<nowiki>$\map \phi y = \begin{cases} y & : y \in \hointr 0 1 \\ 1 & : y = 4 \end{cases}$</nowiki> Then $\phi$ is a [[Definition:Order Isomorphism|order isomorphi...
Subset of Linearly Ordered Space which is Order-Complete and Closed but not Compact
https://proofwiki.org/wiki/Subset_of_Linearly_Ordered_Space_which_is_Order-Complete_and_Closed_but_not_Compact
https://proofwiki.org/wiki/Subset_of_Linearly_Ordered_Space_which_is_Order-Complete_and_Closed_but_not_Compact
[ "Order Topologies" ]
[ "Definition:Ordering", "Definition:Usual Ordering", "Definition:Real Number", "Definition:Order Topology", "Definition:Topological Subspace", "Definition:Complete Lattice", "Definition:Closed Set/Topology", "Definition:Compact Topological Space" ]
[ "Definition:Complete Lattice", "Definition:Order Isomorphism", "Definition:Complete Lattice", "Definition:Closed Set/Topology", "Definition:Relative Complement", "Definition:Open Set/Topology", "Definition:Closed Set/Topology", "Definition:Compact Topological Space", "Definition:Lower Closure/Elemen...
proofwiki-7285
Rule of Explosion/Variant 2
:$\vdash \paren {p \land \neg p} \implies q$
{{BeginTableau|\vdash \paren {p \land \neg p} \implies q}} {{Assumption|1|p \land \neg p}} {{Simplification|2|1|p|1|1}} {{Simplification|3|1|\neg p|1|2}} {{Addition|4|1|p \lor q|2|1}} {{ModusTollendoPonens|5|1|q|4|3}} {{EndTableau|qed}}
:$\vdash \paren {p \land \neg p} \implies q$
{{BeginTableau|\vdash \paren {p \land \neg p} \implies q}} {{Assumption|1|p \land \neg p}} {{Simplification|2|1|p|1|1}} {{Simplification|3|1|\neg p|1|2}} {{Addition|4|1|p \lor q|2|1}} {{ModusTollendoPonens|5|1|q|4|3}} {{EndTableau|qed}}
Rule of Explosion/Variant 2/Proof 1
https://proofwiki.org/wiki/Rule_of_Explosion/Variant_2
https://proofwiki.org/wiki/Rule_of_Explosion/Variant_2/Proof_1
[ "Rule of Explosion" ]
[]
[]
proofwiki-7286
Jordan Curve Theorem
Let $\gamma: \closedint 0 1 \to \R^2$ be a Jordan curve. Let $\Img \gamma$ denote the image of $\gamma$. Then $\R^2 \setminus \Img \gamma$ is a union of two disjoint connected components. Both components are open in $\R^2$, and both components have $\Img \gamma$ as their boundary. One component is bounded, and is calle...
{{proof wanted}} {{Namedfor|Marie Ennemond Camille Jordan|cat = Jordan, C}}
Let $\gamma: \closedint 0 1 \to \R^2$ be a [[Definition:Jordan Curve|Jordan curve]]. Let $\Img \gamma$ denote the [[Definition:Image of Mapping|image]] of $\gamma$. Then $\R^2 \setminus \Img \gamma$ is a [[Definition:Set Union|union]] of two [[Definition:Disjoint Sets|disjoint]] [[Definition:Connected Topological Sp...
{{proof wanted}} {{Namedfor|Marie Ennemond Camille Jordan|cat = Jordan, C}}
Jordan Curve Theorem
https://proofwiki.org/wiki/Jordan_Curve_Theorem
https://proofwiki.org/wiki/Jordan_Curve_Theorem
[ "Jordan Curve Theorem", "Jordan Curves" ]
[ "Definition:Jordan Curve", "Definition:Image (Set Theory)/Mapping/Mapping", "Definition:Set Union", "Definition:Disjoint Sets", "Definition:Connected Topological Space", "Definition:Component (Topology)", "Definition:Open Set/Metric Space", "Definition:Boundary (Topology)", "Definition:Bounded Metri...
[]
proofwiki-7287
Heine-Borel Theorem/Dedekind Complete Space
Let $T = \struct {X, \preceq, \tau}$ be a Dedekind-complete linearly ordered space. Let $Y$ be a non-empty subset of $X$. Then $Y$ is compact {{iff}} $Y$ is closed and bounded in $T$.
=== Sufficient Condition === Let $Y$ be a compact subspace of $T$. From: :Linearly Ordered Space is Hausdorff :Compact Subspace of Hausdorff Space is Closed it follows that $Y$ is closed in $T$. From Compact Subspace of Linearly Ordered Space: Lemma 1, $\struct {Y, \preceq {\restriction_Y} }$ is a complete lattice. {{f...
Let $T = \struct {X, \preceq, \tau}$ be a [[Definition:Dedekind Complete|Dedekind-complete]] [[Definition:Linearly Ordered Space|linearly ordered space]]. Let $Y$ be a [[Definition:Non-Empty Set|non-empty]] [[Definition:Subset|subset]] of $X$. Then $Y$ is [[Definition:Compact Subspace|compact]] {{iff}} $Y$ is [[Defi...
=== Sufficient Condition === Let $Y$ be a [[Definition:Compact Subspace|compact subspace]] of $T$. From: :[[Linearly Ordered Space is Hausdorff]] :[[Compact Subspace of Hausdorff Space is Closed]] it follows that $Y$ is [[Definition:Closed Set (Topology)|closed]] in $T$. From [[Compact Subspace of Linearly Ordered...
Heine-Borel Theorem/Dedekind Complete Space
https://proofwiki.org/wiki/Heine-Borel_Theorem/Dedekind_Complete_Space
https://proofwiki.org/wiki/Heine-Borel_Theorem/Dedekind_Complete_Space
[ "Linearly Ordered Spaces", "Dedekind Completeness Property", "Heine-Borel Theorem" ]
[ "Definition:Dedekind Completeness Property", "Definition:Linearly Ordered Space", "Definition:Non-Empty Set", "Definition:Subset", "Definition:Compact Topological Space/Subspace", "Definition:Closed Set/Topology", "Definition:Bounded Set" ]
[ "Definition:Compact Topological Space/Subspace", "Linearly Ordered Space is Hausdorff", "Compact Subspace of Hausdorff Space is Closed", "Definition:Closed Set/Topology", "Compact Subspace of Linearly Ordered Space/Lemma 1", "Definition:Complete Lattice", "Definition:Closed Set/Topology", "Definition:...
proofwiki-7288
Heine-Borel iff Dedekind Complete
Let $\struct {X, \preceq, \tau}$ be a linearly ordered space. Then $X$ is Dedekind complete {{iff}} every closed, bounded subset of $X$ is compact.
The forward implication follows from Heine-Borel Theorem: Dedekind-Complete Space. Suppose that $X$ is not Dedekind complete. Then $X$ has a non-empty subset $S$ with an upper bound $b$ in $X$ but no supremum in $X$. Let $a \in S$ and let $Y = {\bar \downarrow} S \cap {\bar \uparrow} a$. $Y$ is nonempty and bounded bel...
Let $\struct {X, \preceq, \tau}$ be a [[Definition:Linearly Ordered Space|linearly ordered space]]. Then $X$ is [[Definition:Dedekind Complete|Dedekind complete]] {{iff}} every closed, bounded subset of $X$ is [[Definition:Compact Subspace|compact]].
The forward implication follows from [[Heine-Borel Theorem/Dedekind-Complete Space|Heine-Borel Theorem: Dedekind-Complete Space]]. Suppose that $X$ is not Dedekind complete. Then $X$ has a non-empty subset $S$ with an upper bound $b$ in $X$ but no supremum in $X$. Let $a \in S$ and let $Y = {\bar \downarrow} S \cap ...
Heine-Borel iff Dedekind Complete
https://proofwiki.org/wiki/Heine-Borel_iff_Dedekind_Complete
https://proofwiki.org/wiki/Heine-Borel_iff_Dedekind_Complete
[ "Order Topologies", "Compact Topological Spaces" ]
[ "Definition:Linearly Ordered Space", "Definition:Dedekind Completeness Property", "Definition:Compact Topological Space/Subspace" ]
[ "Heine-Borel Theorem/Dedekind Complete Space" ]
proofwiki-7289
Jordan Polygon Theorem
Let $P$ be a polygon embedded in $\R^2$. Denote the boundary of $P$ as $\partial P$. Then, $\R^2 \setminus \partial P$ is a union of two connected components. Both components are open in $\R^2$. One component is bounded, and is called the interior of $P$. The other component is unbounded, and is called the exterior of ...
=== Lemma === {{:Jordan Polygon Theorem/Lemma 1}}{{qed|lemma}} We show that $\R^2 \setminus \partial P$ is not path-connected. Find any $q_1 \in R^2 \setminus \partial P$ and $\theta \in \R$ such that the ray $\LL_\theta = \set {q_1 + s \map g \theta: s \in \R_{\ge 0} }$ has exactly one crossing of $\partial P$. Find a...
Let $P$ be a [[Definition:Polygon|polygon]] embedded in $\R^2$. Denote the [[Definition:Boundary (Geometry)|boundary]] of $P$ as $\partial P$. Then, $\R^2 \setminus \partial P$ is a [[Definition:Set Union|union]] of two [[Definition:Connected Set (Topology)|connected]] [[Definition:Component (Topology)|components]]....
=== [[Jordan Polygon Theorem/Lemma 1|Lemma]] === {{:Jordan Polygon Theorem/Lemma 1}}{{qed|lemma}} We show that $\R^2 \setminus \partial P$ is not [[Definition:Path-Connected Metric Subspace|path-connected]]. Find any $q_1 \in R^2 \setminus \partial P$ and $\theta \in \R$ such that the [[Definition:Ray (Geometry)|ray...
Jordan Polygon Theorem
https://proofwiki.org/wiki/Jordan_Polygon_Theorem
https://proofwiki.org/wiki/Jordan_Polygon_Theorem
[ "Jordan Polygon Theorem", "Topology" ]
[ "Definition:Polygon", "Definition:Boundary (Geometry)", "Definition:Set Union", "Definition:Connected Set (Topology)", "Definition:Component (Topology)", "Definition:Open Set/Metric Space", "Definition:Bounded Metric Space", "Definition:Jordan Curve/Interior", "Definition:Bounded Metric Space/Unboun...
[ "Jordan Polygon Theorem/Lemma 1", "Definition:Path-Connected/Metric Space/Subset", "Definition:Line/Infinite Half-Line", "Definition:Crossing (Jordan Curve)", "Jordan Polygon Parity Lemma", "Definition:Path (Topology)", "Definition:Path-Connected/Metric Space/Subset", "Definition:Set Union", "Defini...
proofwiki-7290
Jordan Polygon Interior and Exterior Criterion
Let $P$ be a polygon embedded in $\R^2$. Let $q \in \R^2 \setminus \partial P$, where $\partial P$ denotes the boundary of $P$. Let $\mathbf v \in \R^2 \setminus \set \bszero$ be a non-zero vector. Let $\LL = \set {q + s \mathbf v: s \in \R_{\ge 0} }$ be a ray with start point $q$. Let $\map N q \in \N$ be the number o...
From Boundary of Polygon is Jordan Curve, it follows that $\partial P$ is equal to the image of a Jordan curve. From the Jordan Polygon Theorem, it follows that $\Int P$ and $\Ext P$ are path-connected. Then, Jordan Polygon Parity Lemma shows that $\map N q = \map {\operatorname{par} } q$, where $\map {\operatorname{pa...
Let $P$ be a [[Definition:Polygon|polygon]] embedded in $\R^2$. Let $q \in \R^2 \setminus \partial P$, where $\partial P$ denotes the [[Definition:Boundary (Geometry)|boundary]] of $P$. Let $\mathbf v \in \R^2 \setminus \set \bszero$ be a non-[[Definition:Zero Vector|zero]] [[Definition:Plane Vector|vector]]. Let $\...
From [[Boundary of Polygon is Jordan Curve]], it follows that $\partial P$ is equal to the [[Definition:Image of Mapping|image]] of a [[Definition:Jordan Curve|Jordan curve]]. From the [[Jordan Polygon Theorem]], it follows that $\Int P$ and $\Ext P$ are [[Definition:Path-Connected Set|path-connected]]. Then, [[Jorda...
Jordan Polygon Interior and Exterior Criterion
https://proofwiki.org/wiki/Jordan_Polygon_Interior_and_Exterior_Criterion
https://proofwiki.org/wiki/Jordan_Polygon_Interior_and_Exterior_Criterion
[ "Topology" ]
[ "Definition:Polygon", "Definition:Boundary (Geometry)", "Definition:Zero Vector", "Definition:Vector/Real Euclidean Space/Plane Vector", "Definition:Line/Infinite Half-Line", "Definition:Crossing (Jordan Curve)", "Definition:Jordan Curve/Interior", "Definition:Jordan Curve/Exterior", "Definition:Jor...
[ "Boundary of Polygon is Jordan Curve", "Definition:Image (Set Theory)/Mapping/Mapping", "Definition:Jordan Curve", "Jordan Polygon Theorem", "Definition:Path-Connected/Set", "Jordan Polygon Parity Lemma", "Definition:Crossing (Jordan Curve)/Parity", "Jordan Polygon Theorem", "Definition:Bounded Metr...
proofwiki-7291
Closed Set in Linearly Ordered Space
Let $\struct {X, \preceq, \tau}$ be a linearly ordered space. Let $C$ be a subset of $X$. Then $C$ is closed in $X$ {{iff}} for all non-empty subsets $S$ of $C$: :If $s \in X$ is a supremum or infimum of $S$ in $X$, then $s \in C$.
=== Necessary Condition === Suppose that $C$ be closed. Let $S$ be a non-empty subset of $C$. Let $b \in X \setminus C$. We will show that $b$ is not a supremum of $S$. If $b$ is not an upper bound of $S$, then by definition $b$ cannot be a supremum of $S$. Suppose, then, that $b$ is an upper bound of $S$. Since $C$ is...
Let $\struct {X, \preceq, \tau}$ be a [[Definition:Linearly Ordered Space|linearly ordered space]]. Let $C$ be a [[Definition:Subset|subset]] of $X$. Then $C$ is [[Definition:Closed Set (Topology)|closed]] in $X$ {{iff}} for all [[Definition:Non-Empty Set|non-empty]] [[Definition:Subset|subsets]] $S$ of $C$: :If $s ...
=== Necessary Condition === Suppose that $C$ be [[Definition:Closed Set (Topology)|closed]]. Let $S$ be a [[Definition:Non-Empty Set|non-empty]] [[Definition:Subset|subset]] of $C$. Let $b \in X \setminus C$. We will show that $b$ is not a [[Definition:Supremum of Set|supremum]] of $S$. If $b$ is not an [[Definit...
Closed Set in Linearly Ordered Space
https://proofwiki.org/wiki/Closed_Set_in_Linearly_Ordered_Space
https://proofwiki.org/wiki/Closed_Set_in_Linearly_Ordered_Space
[ "Linearly Ordered Spaces" ]
[ "Definition:Linearly Ordered Space", "Definition:Subset", "Definition:Closed Set/Topology", "Definition:Non-Empty Set", "Definition:Subset", "Definition:Supremum of Set", "Definition:Infimum of Set" ]
[ "Definition:Closed Set/Topology", "Definition:Non-Empty Set", "Definition:Subset", "Definition:Supremum of Set", "Definition:Upper Bound of Set", "Definition:Supremum of Set", "Definition:Upper Bound of Set", "Definition:Closed Set/Topology", "Definition:Interval/Ordered Set/Open", "Definition:Ray...
proofwiki-7292
Conditional is Left Distributive over Disjunction/Formulation 1/Forward Implication
:$p \implies \paren {q \lor r} \vdash \paren {p \implies q} \lor \paren {p \implies r}$
{{BeginTableau|p \implies \paren {q \lor r} \vdash \paren {p \implies q} \lor \paren {p \implies r} }} {{Assumption|1|p \implies \paren {q \lor r} }} {{Assumption|2|p}} {{ModusPonens|3|1, 2|q \lor r|1|2}} {{IdentityLaw|4|2|p|2}} {{Assumption|5|q}} {{Implication|6|5|p \implies q|4|5}} {{Addition|7|5|\paren {p \implies ...
:$p \implies \paren {q \lor r} \vdash \paren {p \implies q} \lor \paren {p \implies r}$
{{BeginTableau|p \implies \paren {q \lor r} \vdash \paren {p \implies q} \lor \paren {p \implies r} }} {{Assumption|1|p \implies \paren {q \lor r} }} {{Assumption|2|p}} {{ModusPonens|3|1, 2|q \lor r|1|2}} {{IdentityLaw|4|2|p|2}} {{Assumption|5|q}} {{Implication|6|5|p \implies q|4|5}} {{Addition|7|5|\paren {p \implies ...
Conditional is Left Distributive over Disjunction/Formulation 1/Forward Implication
https://proofwiki.org/wiki/Conditional_is_Left_Distributive_over_Disjunction/Formulation_1/Forward_Implication
https://proofwiki.org/wiki/Conditional_is_Left_Distributive_over_Disjunction/Formulation_1/Forward_Implication
[ "Conditional is Left Distributive over Disjunction" ]
[]
[ "True Statement is implied by Every Statement", "Category:Conditional is Left Distributive over Disjunction" ]
proofwiki-7293
Conditional is Left Distributive over Disjunction/Formulation 1/Reverse Implication
:$\paren {p \implies q} \lor \paren{p \implies r} \vdash p \implies \paren {q \lor r}$
{{BeginTableau|\paren {p \implies q} \lor \paren {p \implies r} \vdash p \implies \paren {q \lor r} }} {{Assumption|1|\paren {p \implies q} \lor \paren {p \implies r} }} {{Assumption|2|p \implies q}} {{Assumption|3|p}} {{ModusPonens|4|2, 3|q|2|3}} {{Addition|5|2, 3|q \lor r|4|1}} {{Implication|6|2|p \implies \paren {q ...
:$\paren {p \implies q} \lor \paren{p \implies r} \vdash p \implies \paren {q \lor r}$
{{BeginTableau|\paren {p \implies q} \lor \paren {p \implies r} \vdash p \implies \paren {q \lor r} }} {{Assumption|1|\paren {p \implies q} \lor \paren {p \implies r} }} {{Assumption|2|p \implies q}} {{Assumption|3|p}} {{ModusPonens|4|2, 3|q|2|3}} {{Addition|5|2, 3|q \lor r|4|1}} {{Implication|6|2|p \implies \paren {q ...
Conditional is Left Distributive over Disjunction/Formulation 1/Reverse Implication
https://proofwiki.org/wiki/Conditional_is_Left_Distributive_over_Disjunction/Formulation_1/Reverse_Implication
https://proofwiki.org/wiki/Conditional_is_Left_Distributive_over_Disjunction/Formulation_1/Reverse_Implication
[ "Conditional is Left Distributive over Disjunction" ]
[]
[ "Category:Conditional is Left Distributive over Disjunction" ]
proofwiki-7294
Factor Principles/Disjunction on Left/Formulation 2
:$\vdash \paren {p \implies q} \implies \paren {\paren {r \lor p} \implies \paren {r \lor q} }$
{{BeginTableau|\vdash \paren {p \implies q} \implies \paren {\paren {r \lor p} \implies \paren {r \lor q} } }} {{Assumption|1|p \implies q}} {{SequentIntro|2|1|\paren {\paren {r \lor p} \implies \paren {r \lor q} }|1|Factor Principles: Disjunction on Left: Formulation 1}} {{Implication|3|1|\paren {p \implies q} \implie...
:$\vdash \paren {p \implies q} \implies \paren {\paren {r \lor p} \implies \paren {r \lor q} }$
{{BeginTableau|\vdash \paren {p \implies q} \implies \paren {\paren {r \lor p} \implies \paren {r \lor q} } }} {{Assumption|1|p \implies q}} {{SequentIntro|2|1|\paren {\paren {r \lor p} \implies \paren {r \lor q} }|1|[[Factor Principles/Disjunction on Left/Formulation 1|Factor Principles: Disjunction on Left: Formulati...
Factor Principles/Disjunction on Left/Formulation 2
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Left/Formulation_2
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Left/Formulation_2
[ "Factor Principles" ]
[]
[ "Factor Principles/Disjunction on Left/Formulation 1" ]
proofwiki-7295
Conditional is Left Distributive over Disjunction/Formulation 2
:$\vdash \paren {p \implies \paren {q \lor r} } \iff \paren {\paren {p \implies q} \lor \paren{p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \lor r} } \iff \paren {\paren {p \implies q} \lor \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \lor r} }} {{SequentIntro|2|1|\paren {p \implies q} \lor \paren {p \implies r}|1|Conditional is Left Distributive over Disjunction: Formulation 1}} {{Implic...
:$\vdash \paren {p \implies \paren {q \lor r} } \iff \paren {\paren {p \implies q} \lor \paren{p \implies r} }$
{{BeginTableau|\vdash \paren {p \implies \paren {q \lor r} } \iff \paren {\paren {p \implies q} \lor \paren {p \implies r} } }} {{Assumption|1|p \implies \paren {q \lor r} }} {{SequentIntro|2|1|\paren {p \implies q} \lor \paren {p \implies r}|1|[[Conditional is Left Distributive over Disjunction/Formulation 1|Condition...
Conditional is Left Distributive over Disjunction/Formulation 2
https://proofwiki.org/wiki/Conditional_is_Left_Distributive_over_Disjunction/Formulation_2
https://proofwiki.org/wiki/Conditional_is_Left_Distributive_over_Disjunction/Formulation_2
[ "Conditional is Left Distributive over Disjunction" ]
[]
[ "Conditional is Left Distributive over Disjunction/Formulation 1", "Conditional is Left Distributive over Disjunction/Formulation 1" ]
proofwiki-7296
Factor Principles/Disjunction on Right/Formulation 2
:$\vdash \paren {p \implies q} \implies \paren {\paren {p \lor r} \implies \paren {q \lor r} }$
{{BeginTableau|\vdash \paren {p \implies q} \implies \paren {\paren {p \lor r} \implies \paren {q \lor r} } }} {{Assumption|1|p \implies q}} {{SequentIntro|2|1|\paren {p \lor r} \implies \paren {q \lor r}|1 |Factor Principles: Disjunction on Right: Formulation 1}} {{Implication|3|1|\paren {p \implies q} \implies \par...
:$\vdash \paren {p \implies q} \implies \paren {\paren {p \lor r} \implies \paren {q \lor r} }$
{{BeginTableau|\vdash \paren {p \implies q} \implies \paren {\paren {p \lor r} \implies \paren {q \lor r} } }} {{Assumption|1|p \implies q}} {{SequentIntro|2|1|\paren {p \lor r} \implies \paren {q \lor r}|1 |[[Factor Principles/Disjunction on Right/Formulation 1|Factor Principles: Disjunction on Right: Formulation 1]...
Factor Principles/Disjunction on Right/Formulation 2
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Right/Formulation_2
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Right/Formulation_2
[ "Factor Principles" ]
[]
[ "Factor Principles/Disjunction on Right/Formulation 1" ]
proofwiki-7297
Factor Principles/Disjunction on Right/Formulation 1
:$p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r}$
{{BeginTableau|p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r} }} {{Premise|1|p \implies q}} {{TheoremIntro|2|r \implies r|Law of Identity: Formulation 2}} {{SequentIntro|3|1|\paren {p \lor r} \implies \paren {q \lor r}|1, 2|Constructive Dilemma}} {{EndTableau}} {{qed}}
:$p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r}$
{{BeginTableau|p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r} }} {{Premise|1|p \implies q}} {{TheoremIntro|2|r \implies r|[[Law of Identity/Formulation 2|Law of Identity: Formulation 2]]}} {{SequentIntro|3|1|\paren {p \lor r} \implies \paren {q \lor r}|1, 2|[[Constructive Dilemma/Formulation 1|Constru...
Factor Principles/Disjunction on Right/Formulation 1/Proof 1
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Right/Formulation_1
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Right/Formulation_1/Proof_1
[ "Factor Principles" ]
[]
[ "Law of Identity/Formulation 2", "Constructive Dilemma/Formulation 1" ]
proofwiki-7298
Factor Principles/Disjunction on Right/Formulation 1
:$p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r}$
{{BeginTableau|p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r} }} {{Premise|1|p \implies q}} {{Assumption|2|p \lor r}} {{Assumption|3|r}} {{Addition|4|3|q \lor r|3|2}} {{Assumption|5|p}} {{ModusPonens|6|1, 5|q|1|5}} {{Addition|7|1, 5|q \lor r|6|1}} {{ProofByCases|8|1, 2|q \lor r|2|5|7|3|4}} {{Implicati...
:$p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r}$
{{BeginTableau|p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r} }} {{Premise|1|p \implies q}} {{Assumption|2|p \lor r}} {{Assumption|3|r}} {{Addition|4|3|q \lor r|3|2}} {{Assumption|5|p}} {{ModusPonens|6|1, 5|q|1|5}} {{Addition|7|1, 5|q \lor r|6|1}} {{ProofByCases|8|1, 2|q \lor r|2|5|7|3|4}} {{Implicati...
Factor Principles/Disjunction on Right/Formulation 1/Proof 2
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Right/Formulation_1
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Right/Formulation_1/Proof_2
[ "Factor Principles" ]
[]
[]
proofwiki-7299
Factor Principles/Disjunction on Right/Formulation 1
:$p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r}$
{{BeginTableau|p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r} }} {{Premise|1|p \implies q}} {{Assumption|2|p \lor r}} {{Commutation|3|2|r \lor p|2|Disjunction}} {{SequentIntro|4|1|\paren {r \lor p} \implies \paren {r \lor q}|1|Factor Principles/Disjunction on Left/Formulation 1}} {{ModusPonens|5|1,2|r...
:$p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r}$
{{BeginTableau|p \implies q \vdash \paren {p \lor r} \implies \paren {q \lor r} }} {{Premise|1|p \implies q}} {{Assumption|2|p \lor r}} {{Commutation|3|2|r \lor p|2|Disjunction}} {{SequentIntro|4|1|\paren {r \lor p} \implies \paren {r \lor q}|1|[[Factor Principles/Disjunction on Left/Formulation 1]]}} {{ModusPonens|5|1...
Factor Principles/Disjunction on Right/Formulation 1/Proof 3
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Right/Formulation_1
https://proofwiki.org/wiki/Factor_Principles/Disjunction_on_Right/Formulation_1/Proof_3
[ "Factor Principles" ]
[]
[ "Factor Principles/Disjunction on Left/Formulation 1" ]